V7/usr/lib/learn/morefiles.a
eL0 Z #next
0.1a 10
L0.1a #print
In the basic files course you learned about the "ls" command
for listing the names of files in the current directory.
You will now learn some of the extra abilities of "ls".
UNIX maintains a lot more information about a file than just
its name; this extra information includes the size of the
file, the date and time it was last changed, the owner,
and scattered other miscellany. To see this "long" list of information,
use the command "ls -l". (That's an "ell", not a "one".)
The "-l" is called an "optional argument",
since it may or may not be present.
To begin, try just "ls -l", then type "ready".
#create junk
this is garbage
#copyin
#user
#uncopyin
#match ls -l
#log
#next
0.1b 10
aL0.1b F #print
When you ask for "ls -l", the first line,
which says "total N", is a measure of how much
file space is used by the files in this directory.
The part of the listing that says something like
"-rw-rw-r--" tells you the read and write
permissions for the file -- in effect,
who can do what to it.
The second field is the number of "links" to the file.
We won't worry about these two right now.
The name in the third field is the owner of the file.
The fourth field is the size of the file in characters,
which is often interesting. The rest of the listing is
the date and time the file was last changed, and its name.
What is the largest file in this directory?
(Don't use the previous list - I've changed things.)
Type "answer name", where "name" is the name of the
largest file.
#create big
stuff
#create biggest
not really
#create X1
morestuf
#create m
moremore moremore moremore moremore moremore moremore moremore moremore moremore
moremore moremore moremore moremore moremore moremore moremore moremore moremore
moremore moremore moremore moremore moremore moremore moremore moremore moremore
moremore moremore moremore moremore moremore moremore moremore moremore moremore
moremore moremore moremore moremore moremore moremore moremore moremore moremore
#copyin
#user
#uncopyin
#match m
#bad biggest
You didn't look at the sizes, did you?
#bad big
You didn't look at the sizes, did you?
#log
#next
0.1c 10
mL0.1c ǽ ##print
How many characters are there in the file whose name begins
with "r"? Type "answer N", where N is the number of characters
you found.
#create ref
hello world
#create Ref
hello
#copyin
#user
#uncopyin
#match 12
#bad 6
"R" is not___ the same as "r". Look again.
#log
#next
0.1d 10
uL0.1d #print
Is the file "ref" bigger than the file "ref1"?
Answer yes or no.
#create ref
now is the time.
#create ref1
now is the time for all good men.
#copyin
#user
#uncopyin
#match no
#log
#next
0.1e 10
cL0.1e #print
The list of file names from "ls" can also be obtained
sorted by the date the file was most recently changed,
with the newest files listed first. This list is
obtained by typing "ls -t".
What is the oldest file in this directory?
Type "answer name", where "name" is the oldest file.
#create X1
stuff
#create X2
stuff
#create X3
stuff
#
#copyin
#user
#uncopyin
ls -t | tail -1 >X1
tail -1 .copy >test
#cmp X1 test
#log
#next
0.1f 10
L0.1f #print
You can combine the optional arguments to "ls"; for example
you can get the "long" list sorted by time of last change
by saying
ls -lt
Try that, then type "ready".
#copyin
#user
#uncopyin
#match ls -lt
#log
#next
0.1g 10
L0.1g ~ #print
Is "ls -tl" identical to "ls -lt"? Try it,
then type yes or no.
#copyin
#user
#uncopyin
#match yes
#log
#next
1.1a 10
L1.1a h1#print
One of the more useful programs on Unix is "spell", which
looks for spelling mistakes in a set of files. Although spell
is not perfect, it does a reasonable job of presenting you
with a list of possibilities. To look for mistakes in a set
of files, you simply say
spell filenames
and of course you can use shorthands like *, ? and [] to name
the files. For practice, there are some files whose names begin
with "memo" in this directory; somewhere in one of them
is a legitimate spelling mistake. Use spell to find it, then
type "answer word", where "word" is the mistake.
Spell may also output a number of words
that aren't mistakes; you may have to select real errors
from the false ones.
By the way, spell takes a minute to run;
go get a cup of coffee or something while you wait.
#create memo1
(This comes from a federalist paper by alexander hamilton.)
It has been mentioned as one of the advantages to be expected
from the cooperation of the Senate, in the business
of appointments, that it would contribute to the
stability of the administration. The consent of that body
would be necessary to displace as well as to appoint. A
change of the Chief Magistrate, therefore, would not occasion
so violent or so general a revolution in the officers
of the government as might be expected if he were the
sole disposer of offices. Where a man in any station had
given satisfactory evidence of his fitness for it, a new
President would be restrained from attempting a change
in favor of a person more agreeable to him by the apprehension
that a discountenance of the Senate might frustrate
the attempt, and bring some degree of discredit
upon himself. Those who can best estimate the value of
a steady administration will be most disposed to prize a
provision which connects the official existence of public
men with the approbation or disapprobation of that body
which, from the greater permanency of its own composition,
will in all probability be less subject to inconstancy
than any other member of the government.
To this union of the Senate with the President, in the
article of appointments, it has in some cases been suggested
that it would serve to give the President an undue
influence over the Senate, and in others that it would
have an opposite tendency - a strong proof that neither
suggestion is true.
To state the first in its proper form is to refute it. It
amounts to this: the President would have an improper
influence over the Senate, because the Senate would
have the power of restraining him. This is an absurdity in
terms. It cannot admit of a doubt that the entire power
of appointment would enable him much more effectually
to establish a dangerous empire over that body than a
mere power of nomination subject to their control.
Let us take a view of the converse of the proposition:
"the Senate would influence the executive." As I have
had occasion to remark in several other instances, the indistinctness
of the objection forbids a precise answer. In
what manner is this influence to be exerted? In relation
to what objects? The power of influencing a person, in
the sense in which it is here used, must imply a power of
conferring a benefit upon him. How could the Senate
confer a benefit upon the President by the manner of employing
their right of negative upon his nominations? If it
be said they might sometimes gratify him by an acquiescence
in a favorite choice, when public motives might dictate a
different conduct, I answer that the instances in which the
President could be personally interested in the result would
be too few to admit of his being materially affected by the
#create memo2
compliances of the Senate. Besides this, it is evident that
the POWER which can originate the disposition of honors
and emoluments is more likely to attract than to be attracted
by the POWER which can merely obstruct their
course. If by influencing the President be want restraining
him, this is precisely what must have been intended.
And it has been shown that the restraint would be salutary,
at the same time that it would not be such as to
destroy a single advantage to be looked for from the uncontrolled
agency of that magistrate. The right of nomination
would produce all the good, without the ill.
Upon a comparison of the plan for the appointment of
the officers of the proposed government with that which
is established by the constitution of this State, a decided
preference must be given to the former. In that plan the
power of nomination is unequivocally vested in the executive.
And as there would be a necessity for submitting
each nomination to the judgment of an entire branch of
the legislature, the circumstances attending an appointment,
from the mode of conducting it, would naturally
become matters of notoriety, and the public would
be at no loss to determine what part had been performed
by the different actors. The blame of a bad nomination
would fall upon the President singly and absolutely. The
censure of rejecting a good one would lie entirely at the
door of the senate, aggravated by the consideration
of their having counteracted the good intentions of the
executive. If an ill appointment should be made, the executive,
for nominating, and the Senate, for approving,
would participate, though in different degrees, in the
opprobrium and disgrace.
The reverse of all this characterizes the manner of appointment
in this State. The council of appointment consists
of from three to five persons, of whom the governor
is always one. This small body, shut up in a private
apartment, impenetrable to the public eye, proceed to the
execution of the trust committed to them. It is known
that the governor claims the right of nomination upon
the strength of some ambiguous expressions in the Constitution;
but it is not known to what extent, or in what
manner he exercises it; nor upon what occasions he is
contradicted or opposed. The censure of a bad appointment,
on account of the uncertainty of its author and for
want of a determinate object, has neither poignancy nor
duration. And while an unbounded field for cabal and intrigue
lies open, all idea of responsibility is lost. The
most that the public can know is that the governor
claims the right of nomination; that two out of the inconsiderable
number of four men can too often be managed
without much difficulty; that if some of the members of a
#create memo3
particular council should happen to be of an uncomplying
character, it is frequently not impossible to get rid of their
opposition by regulating the times of meeting in such a
manner as to render their attendance inconvenient; and
that from whatever cause it may proceed, a great
number of very improper appointments are from time to
time made. Whether a governor of this State avails himself
of the ascendant, he must necessarily have in this
delicate and important part of the administration to prefer
to offices men who are best qualified for them; or
whether he prostitutes that advantage to the advancement
of persons whose chief merit is their implicit devotion to
his will and to the support of a despicable and dangerous
system of personal influence are questions which, unfortunately
for the community, can only be the subjects
of speculation and conjecture.
Every mere council of appointment, however constituted,
will be a conclave in which cabal and intrigue will
have their full scope. Their number, without an unwarrantable
increase of expense, cannot be large enough to
preclude a facility of combination. And as each member
will have his friends and connections to provide for,
the desire of mutual gratification will beget a scandalous
bartering of votes and bargaining for places. The private
attachments of one man might easily be satisfied, but to
satisfy the private attachments of a dozen, or of twenty
men, would occasion a monopoly of all the principal employments
of the government in a few families and
would lead more directly to an aristocracy or an oligarchy
than any measure that could be contrived. If, to avoid an
accumulation of offices, there was to be a frequent change
in the persons who were to be a frequent change
in the persons who were to compose the council, this
would involve the mischiefs of a mutable administration
in their full extent. Such a council would also be more
liable to executive influence than the Senate, because
they would be fewer in number, and would act less immediately
under the public inspection. Such a council, in
fine, as a substitute for the plan of the convention, would
be productive of an increase of expense, a multiplication
of the evils which spring from favoritism and intrigue in
the distribution of public honors, a decrease of stability
in the administration of the government, and a diminution
of the security against an undue influence of the
executive. And yet such a council has been warmly contended
for as an essential amendment in the proposed
Constitution.
I could not with propriety conclude my observations
on the subject of appointments without taking notice of
a scheme for which there have appeared some, though
#create memo4
but a few advocates; I mean that of uniting the House of
Representatives in the power of making them. I shall,
however, do little more than mention it, as I cannot
imagine that it is likely to gain the countenance of any
considerable part of the community. A body so fluctuating
and at the same time so numerous can never be
deemed proper for the exercise of that power. Its unfitness
will appear manifest to all when it is recollected that
in half a century it may consist of three or four hundred
persons. All the advantages of the stability, both of the
Executive and of the Senate, would be defeated by this
union, and infinite delays and embarrassments would be
occasioned. The exampled of most of the States in their
local constitutions encourages us to reprobate the idea.
The only remaining powers of the executive are comprehended
in giving information to Congress of the state
of the Union; in recommending to their consideration
such measures as he shall judge expedient; in convening
them, or either branch, upon extraordinary occasions; in
adjourning them when they cannot themselves agree upon
the time of adjournment; in receiving ambassadors and
other public ministers; in faithfully executing the laws;
and in commissioning all the officers of the United States.
Except some cavils about the power of convening either
house of the legislature, and that of receiving ambassadors,
no objection has been made to this class of
authorities; nor could they possibly admit of any. It required,
indeed, an insatiable avidity for censure to invent
exceptions to the parts which have been excepted to. In
regard to the power of convening either house of the legislature
I shall barely remark that in respect to the Senate,
at least, we can readily discover a good reason for it. As
this body has a concurrent power with the executive in
the article of treaties, it might often be necessary to call
it together with a view to this object, when it would be
unnecessary and improper to convene the House of Representatives.
As to the reception of ambassadors, what I
have said in a former paper will furnish a sufficient answer.
We have now completed a survy of the structure and
powers of the executive department which, I have endeavored
to show, combines, as far as republican principles
will admit, all the requisites to energy. The
remaining inquiry is: does it also combine the requisites
to safety, in the republican sense - due dependence on
the people, a due responsibility? The answer to this question
has been anticipated in the investigation of its other
characteristics, and is satisfactorily deducible from these
circumstances; the election of the President once in four
years by persons immediately chosen by the people for
that purpose, and his being at all times liable to impeachment,
trial, dismission from office, incapacity to serve
in any other, and to the forfeiture of life and estate by subsequent
prosecution in the common course of law. But
these precautions, great as they are, are not the only
ones which the plan of the convention has provided in
favor of the public security. In the only instances in which
the abuse of the executive authority was materially to be
feared, the chief Magistrate of the United States, would,
by that plan, be subjected to the control of a branch of
the legislative body. What more can an enlightened and
reasonable people desire?
#copyin
#user
#uncopyin
#match survy
#log
#next
1.1b 10
L1.1b D 1#print
Now that you know what word is wrong, you still have to find
it in one of the memo files so you can correct it. One way
is to use the text editor "ed", but that is rather slow. Better
is to use the pattern-finding program "grep", which looks through
a set of files to find a particular word. To find all occurrences
of "glop" in the files tom, dick and harry, you need only type
grep 'glop' tom dick harry
The first thing is the word that grep is to search for;
any remaining names are file names, which are searched in order.
The quotes around the word to be searched for aren't
always necessary, but it's a good habit to use them
anyway. Later on we'll see some examples where they are really
needed.
Use grep to find the memo file that contains the spelling error,
and type "answer name", where "name" is the file you decide on.
#create memo1
(This comes from a federalist paper by alexander hamilton.)
It has been mentioned as one of the advantages to be expected
from the cooperation of the Senate, in the business
of appointments, that it would contribute to the
stability of the administration. The consent of that body
would be necessary to displace as well as to appoint. A
change of the Chief Magistrate, therefore, would not occasion
so violent or so general a revolution in the officers
of the government as might be expected if he were the
sole disposer of offices. Where a man in any station had
given satisfactory evidence of his fitness for it, a new
President would be restrained from attempting a change
in favor of a person more agreeable to him by the apprehension
that a discountenance of the Senate might frustrate
the attempt, and bring some degree of discredit
upon himself. Those who can best estimate the value of
a steady administration will be most disposed to prize a
provision which connects the official existence of public
men with the approbation or disapprobation of that body
which, from the greater permanency of its own composition,
will in all probability be less subject to inconstancy
than any other member of the government.
To this union of the Senate with the President, in the
article of appointments, it has in some cases been suggested
that it would serve to give the President an undue
influence over the Senate, and in others that it would
have an opposite tendency - a strong proof that neither
suggestion is true.
To state the first in its proper form is to refute it. It
amounts to this: the President would have an improper
influence over the Senate, because the Senate would
have the power of restraining him. This is an absurdity in
terms. It cannot admit of a doubt that the entire power
of appointment would enable him much more effectually
to establish a dangerous empire over that body than a
mere power of nomination subject to their control.
Let us take a view of the converse of the proposition:
"the Senate would influence the executive." As I have
had occasion to remark in several other instances, the indistinctness
of the objection forbids a precise answer. In
what manner is this influence to be exerted? In relation
to what objects? The power of influencing a person, in
the sense in which it is here used, must imply a power of
conferring a benefit upon him. How could the Senate
confer a benefit upon the President by the manner of employing
their right of negative upon his nominations? If it
be said they might sometimes gratify him by an acquiescence
in a favorite choice, when public motives might dictate a
different conduct, I answer that the instances in which the
President could be personally interested in the result would
be too few to admit of his being materially affected by the
#create memo2
compliances of the Senate. Besides this, it is evident that
the POWER which can originate the disposition of honors
and emoluments is more likely to attract than to be attracted
by the POWER which can merely obstruct their
course. If by influencing the President be want restraining
him, this is precisely what must have been intended.
And it has been shown that the restraint would be salutary,
at the same time that it would not be such as to
destroy a single advantage to be looked for from the uncontrolled
agency of that magistrate. The right of nomination
would produce all the good, without the ill.
Upon a comparison of the plan for the appointment of
the officers of the proposed government with that which
is established by the constitution of this State, a decided
preference must be given to the former. In that plan the
power of nomination is unequivocally vested in the executive.
And as there would be a necessity for submitting
each nomination to the judgment of an entire branch of
the legislature, the circumstances attending an appointment,
from the mode of conducting it, would naturally
become matters of notoriety, and the public would
be at no loss to determine what part had been performed
by the different actors. The blame of a bad nomination
would fall upon the President singly and absolutely. The
censure of rejecting a good one would lie entirely at the
door of the senate, aggravated by the consideration
of their having counteracted the good intentions of the
executive. If an ill appointment should be made, the executive,
for nominating, and the Senate, for approving,
would participate, though in different degrees, in the
opprobrium and disgrace.
The reverse of all this characterizes the manner of appointment
in this State. The council of appointment consists
of from three to five persons, of whom the governor
is always one. This small body, shut up in a private
apartment, impenetrable to the public eye, proceed to the
execution of the trust committed to them. It is known
that the governor claims the right of nomination upon
the strength of some ambiguous expressions in the Constitution;
but it is not known to what extent, or in what
manner he exercises it; nor upon what occasions he is
contradicted or opposed. The censure of a bad appointment,
on account of the uncertainty of its author and for
want of a determinate object, has neither poignancy nor
duration. And while an unbounded field for cabal and intrigue
lies open, all idea of responsibility is lost. The
most that the public can know is that the governor
claims the right of nomination; that two out of the inconsiderable
number of four men can too often be managed
without much difficulty; that if some of the members of a
#create memo3
particular council should happen to be of an uncomplying
character, it is frequently not impossible to get rid of their
opposition by regulating the times of meeting in such a
manner as to render their attendance inconvenient; and
that from whatever cause it may proceed, a great
number of very improper appointments are from time to
time made. Whether a governor of this State avails himself
of the ascendant, he must necessarily have in this
delicate and important part of the administration to prefer
to offices men who are best qualified for them; or
whether he prostitutes that advantage to the advancement
of persons whose chief merit is their implicit devotion to
his will and to the support of a despicable and dangerous
system of personal influence are questions which, unfortunately
for the community, can only be the subjects
of speculation and conjecture.
Every mere council of appointment, however constituted,
will be a conclave in which cabal and intrigue will
have their full scope. Their number, without an unwarrantable
increase of expense, cannot be large enough to
preclude a facility of combination. And as each member
will have his friends and connections to provide for,
the desire of mutual gratification will beget a scandalous
bartering of votes and bargaining for places. The private
attachments of one man might easily be satisfied, but to
satisfy the private attachments of a dozen, or of twenty
men, would occasion a monopoly of all the principal employments
of the government in a few families and
would lead more directly to an aristocracy or an oligarchy
than any measure that could be contrived. If, to avoid an
accumulation of offices, there was to be a frequent change
in the persons who were to be a frequent change
in the persons who were to compose the council, this
would involve the mischiefs of a mutable administration
in their full extent. Such a council would also be more
liable to executive influence than the Senate, because
they would be fewer in number, and would act less immediately
under the public inspection. Such a council, in
fine, as a substitute for the plan of the convention, would
be productive of an increase of expense, a multiplication
of the evils which spring from favoritism and intrigue in
the distribution of public honors, a decrease of stability
in the administration of the government, and a diminution
of the security against an undue influence of the
executive. And yet such a council has been warmly contended
for as an essential amendment in the proposed
Constitution.
I could not with propriety conclude my observations
on the subject of appointments without taking notice of
a scheme for which there have appeared some, though
#create memo4
but a few advocates; I mean that of uniting the House of
Representatives in the power of making them. I shall,
however, do little more than mention it, as I cannot
imagine that it is likely to gain the countenance of any
considerable part of the community. A body so fluctuating
and at the same time so numerous can never be
deemed proper for the exercise of that power. Its unfitness
will appear manifest to all when it is recollected that
in half a century it may consist of three or four hundred
persons. All the advantages of the stability, both of the
Executive and of the Senate, would be defeated by this
union, and infinite delays and embarrassments would be
occasioned. The exampled of most of the States in their
local constitutions encourages us to reprobate the idea.
The only remaining powers of the executive are comprehended
in giving information to Congress of the state
of the Union; in recommending to their consideration
such measures as he shall judge expedient; in convening
them, or either branch, upon extraordinary occasions; in
adjourning them when they cannot themselves agree upon
the time of adjournment; in receiving ambassadors and
other public ministers; in faithfully executing the laws;
and in commissioning all the officers of the United States.
Except some cavils about the power of convening either
house of the legislature, and that of receiving ambassadors,
no objection has been made to this class of
authorities; nor could they possibly admit of any. It required,
indeed, an insatiable avidity for censure to invent
exceptions to the parts which have been excepted to. In
regard to the power of convening either house of the legislature
I shall barely remark that in respect to the Senate,
at least, we can readily discover a good reason for it. As
this body has a concurrent power with the executive in
the article of treaties, it might often be necessary to call
it together with a view to this object, when it would be
unnecessary and improper to convene the House of Representatives.
As to the reception of ambassadors, what I
have said in a former paper will furnish a sufficient answer.
We have now completed a survy of the structure and
powers of the executive department which, I have endeavored
to show, combines, as far as republican principles
will admit, all the requisites to energy. The
remaining inquiry is: does it also combine the requisites
to safety, in the republican sense - due dependence on
the people, a due responsibility? The answer to this question
has been anticipated in the investigation of its other
characteristics, and is satisfactorily deducible from these
circumstances; the election of the President once in four
years by persons immediately chosen by the people for
that purpose, and his being at all times liable to impeachment,
trial, dismission from office, incapacity to serve
in any other, and to the forfeiture of life and estate by subsequent
prosecution in the common course of law. But
these precautions, great as they are, are not the only
ones which the plan of the convention has provided in
favor of the public security. In the only instances in which
the abuse of the executive authority was materially to be
feared, the chief Magistrate of the United States, would,
by that plan, be subjected to the control of a branch of
the legislative body. What more can an enlightened and
reasonable people desire?
#copyin
#user
#uncopyin
#match memo4
#log
#next
1.1c 10
hL1.1c 9 #print
In this directory is a file named for an unsuccessful king.
Read it and do what it tells you.
#create Elizabeth1
1. She was not a king
2. She was generally successful
#create George3
Does the file George3 contain a backspace character
any where in it? Figure it out with grep, then type
"answer N", where N is the line number where you found it.
Type "answer 0" if there is no backspace.
#copyin
#user
#uncopyin
#match 2
#log
#next
1.1d 10
aL1.1d po
#print
Suppose you want to print all lines in the file "memo"
that contain a question mark "?". Since the question mark
is an abbreviation character (as in "ls ?"), you
have to make sure that the command interpreter doesn't
try to interpret it, but instead passes it to "grep"
as a literal question mark.
The way to do this is simply to enclose it in quotes,
as in
grep '?' files...
Use "grep" to find all the lines with question marks,
then type "ready".
#create memo
(This comes from a federalist paper by alexander hamilton.)
It has been mentioned as one of the advantages to be expected
from the cooperation of the Senate, in the business
of appointments, that it would contribute to the
stability of the administration. The consent of that body
would be necessary to displace as well as to appoint. A
change of the Chief Magistrate, therefore, would not occasion
so violent or so general a revolution in the officers
of the government as might be expected if he were the
sole disposer of offices. Where a man in any station had
given satisfactory evidence of his fitness for it, a new
President would be restrained from attempting a change
in favor of a person more agreeable to him by the apprehension
that a discountenance of the Senate might frustrate
the attempt, and bring some degree of discredit
upon himself. Those who can best estimate the value of
a steady administration will be most disposed to prize a
provision which connects the official existence of public
men with the approbation or disapprobation of that body
which, from the greater permanency of its own composition,
will in all probability be less subject to inconstancy
than any other member of the government.
To this union of the Senate with the President, in the
article of appointments, it has in some cases been suggested
that it would serve to give the President an undue
influence over the Senate, and in others that it would
have an opposite tendency - a strong proof that neither
suggestion is true.
To state the first in its proper form is to refute it. It
amounts to this: the President would have an improper
influence over the Senate, because the Senate would
have the power of restraining him. This is an absurdity in
terms. It cannot admit of a doubt that the entire power
of appointment would enable him much more effectually
to establish a dangerous empire over that body than a
mere power of nomination subject to their control.
Let us take a view of the converse of the proposition:
"the Senate would influence the executive." As I have
had occasion to remark in several other instances, the indistinctness
of the objection forbids a precise answer. In
what manner is this influence to be exerted? In relation
to what objects? The power of influencing a person, in
the sense in which it is here used, must imply a power of
conferring a benefit upon him. How could the Senate
confer a benefit upon the President by the manner of employing
their right of negative upon his nominations? If it
be said they might sometimes gratify him by an acquiescence
in a favorite choice, when public motives might dictate a
different conduct, I answer that the instances in which the
President could be personally interested in the result would
be too few to admit of his being materially affected by the
#create Ref
what manner is this influence to be exerted? In relation
to what objects? The power of influencing a person, in
their right of negative upon his nominations? If it
#create 1
#create x
#copyout
#user
#uncopyout
tail -3 .ocopy >X1
#cmp X1 Ref
#log
#next
2.1a 10
L2.1a p #print
Most of the programs we have studied so far produce their
output on the terminal -- examples are "ls", "spell", "grep",
"date", "who", and so on. (Of course, some do not, like
"mv", "cp", and "rm".) In any case, it is sometimes useful
to be able to capture the output of a program in a file,
so it can be used in some later processing. This is very easy.
For example, to get the current date and time in a file called
"now", you need only type
date >now
The symbol ">" tells the command interpreter that output
is to go into the file whose name follows. If the file already
exists, its old contents will be clobbered, so use discretion.
Your task is to make a list of the files in this directory
in the file "foo".
When you have finished, type "ready".
#create X1
#create junk
#create glop
#create junk1
asdfadfaf
#create junk2
qerqerqrq
#user
ls >X1
#cmp X1 foo
#log
#next
2.1b 10
eL2.1b #print
Now make a list of the files in this directory whose
names begin with "t" in the file "foo".
Type "ready" when you are done.
#create X1
#create foo
#create this
#create Ref
that
theother
this
#create that
#create theother
#user
#cmp foo Ref
#log
#next
2.1c 10
1L2.1c B V#print
This time you have to get a list of the files whose names begin
with "memo", but sorted in order of last change, most recent first,
as produced by "ls -t". Get the list in file "gorp",
then type "ready".
#create memo1
first line
#create memo3
third line
#create memo2
second line
#user
ls -t memo* >X1
#cmp X1 gorp
#log
#next
2.1d 10
L2.1d #print
If you type "ls >list", does the name "list" appear in the file
called "list"? Figure it out, then type yes or no.
#copyin
#user
#uncopyin
#match yes
#log
#next
2.1e 10
iL2.1e #print
If you make a mistake and type something like
xxxxx >precious
where "xxxxx" is not___ the name of a legal UNIX
command, what happens to the file "precious"?
In this directory, there are several precious files.
Experiment to see what happens. When you have decided,
type "answer harmless" if nothing happens to the files,
or "answer disaster" if the file is clobbered.
#create precious
I am precious.
#create precious1
So am I.
#create precious2
Me too.
#copyin
#user
#uncopyin
#match disaster
#log
#next
2.1f 10
eL2.1f
} +#print
Obtain a long listing (with "ls -l") of all files in this directory
whose names begin with capital letters, in a file
called "names".
Type "ready" when you're done.
#create STUFF
#create Nonsense
this is junk
#create abc
#create def
#
ls -l [A-Z]* >x1
#user
#cmp x1 names
#log
#next
3.1a 10
lL3.1a %#print
The notation ">" can be used by most programs to capture
output on a file. For example,
cat henry >james
makes a copy of "henry" in the file "james"; in fact this is
essentially identical to
cp henry james
"cat" is a bit more flexible, though, since you can concatenate
several files onto one output. Remember that
cat tom dick harry
copies all three files onto the terminal?
In this directory is a file named "john".
Make a file called "mary" that contains ___two copies of "john".
Type "ready" when you're done.
#create john
Now is the time for all good
men to come to the aid of their
party
#create X1
Now is the time for all good
men to come to the aid of their
party
Now is the time for all good
men to come to the aid of their
party
#user
#cmp X1 mary
#log
#next
3.1b 10
rL3.1b D #print
How many spelling mistakes are there in the file "Ref",
according to "spell"?
Type "answer N", where N is the number you decide on.
#create Ref
Bianchi
Blue
Feldman
McIlroy
Roome
Rosin
Rosler
Aho
Bourne
Dvorak
Haley
Harris
Holt
Johnson
Mashey
Mitze
Muha
Nelson
Pinson
Plauger
Spivack
Thompson
Weinberger
Lesk
Ossanna
#
spell Ref | %s/../lcount >X2 &
#copyin
#user
#uncopyin
tail -1 .copy >X1
#cmp X2 X1
#log
#next
3.1c 10
nL3.1c #print
So far the only printing program we have seen
is "cat", which just copies one or more files
onto the terminal (or perhaps onto a file when used
with ">").
The next step up is the program "pr", which
prints files so that each file begins on a
new page, and the top of each page contains the date
and time the file was changed, and a running page number.
Use a single "pr" to print the two files in this directory
whose names begin with "fed".
What page number is printed on the last page? Type "answer N"
where N is the page number.
#create fed1
After an unequivocal experience of the inefficacy of
the subsisting federal government, you are called upon to
deliberate on a new Constitution for the United States
of America. The subject speaks its own importance;
comprehending in its consequences nothing less than the
existence of the union, the safety and welfare of the
parts of which it is composed, the fate of an empire in many
respects the most interesting in the world.
#create fed2
It has been frequently remarked that it seems to have been
reserved to the people of this country, by their conduct and
example, to decide the important question, whether
societies of men are really capable or not of establishing
good government from reflection and choice, or whether
they are forever destined to depend for their political
constitutions on accident and force. If there be any truth
in the remark, the crisis at which we are arrived may with
propriety be regarded as the era in which that
decision is to be made; and a wrong election of the part
we shall act may, in this view, deserve to be considered as
the general misfortune of mankind.
#copyin
#user
#uncopyin
#match 1
#log
#next
3.1d
L3.1d 1{ #print
The pr command has a number of other capabilities besides simple
printing of files. Probably the most useful is that it can do
multi-column printing. This is controlled by an optional
argument:
pr -3 filenames
will print in 3-column format, and
pr -5 filenames
prints in five columns. You can use any number in place of 3 and 5,
although as you get more columns they become narrower
so things will fit.
Notice that the optional argument comes ______before the files names.
In this directory there is a list of words. Find the list, print
it in two columns, and find out what word appears at the top
of the second column. Type "answer WORD", where WORD
is the word you decide on.
#create wordlist
a
aardvark
aardwolf
Aaron
Aaronic
Ab
aba
abaca
abaci
aback
abacus
abacuses
abaft
abalone
abandon
abandoned
abandoner
abandonment
abase
abasement
abash
abashment
abate
abatement
abater
abatis
abatises
abattoir
abaxial
abbacy
Abbasid
abbatial
abbe'
abbess
Abbevillian
abbey
abbot
abbreviate
abbreviation
abbreviator
Abby
Abc
Abcs
Abc's
abdicable
abdicate
abdication
abdicator
abdomen
abdominal
abdominally
abdominous
abduce
abducent
abduct
abduction
abductor
abeam
abecedarian
abed
Abel
abele
abelmosk
aberrance
aberrancy
aberrant
aberrantly
aberration
aberrational
abet
abetment
abetted
abetter
abetting
abettor
abeyance
abeyant
abhominable
abhor
abhorred
abhorrence
abhorrent
abhorrently
abhorrer
abhorring
Abib
abidance
abide
abided
abider
abiding
Abigail
abigail
ability
abiogeneses
abiogenesis
abiogenetic
abiogenetical
abiogenetically
abiogenist
#copyin
#user
#uncopyin
#create script
/^a/s/.* //
.w X1
w
q
#
pr -2 wordlist >foo
ed - foo <script
tail -1 .copy >X2
#cmp X1 X2
#log
#next
3.1e 10
bL3.1e V {#print
Of course you can collect the output from "pr" in a file,
just as you can with "cat". For practice, there are several
files in this directory whose names begin with "word".
Prepare a list (with "pr", one file per page)
of these files in the file "neat".
Type "ready" when you have finished.
#create word1
a
aard-vark
aard-wolf
Aar-on
Aa-ron-ic
Ab
aba
ab-a-ca
aba-ci
aback
aba-cus
aba-cus-es
abaft
ab-a-lo-ne
aban-don
aban-doned
aban-don-er
aban-don-ment
abase
abase-ment
abash
abash-ment
abate
abate-ment
abat-er
ab-a-tis
ab-a-tis-es
ab-at-toir
ab-ax-i-al
ab-ba-cy
#create word2
Ab-bas-id
ab-ba-tial
ab-be'
ab-bess
Abbe-vil-li-an
ab-bey
ab-bot
ab-bre-vi-ate
ab-bre-vi-a-tion
ab-bre-vi-a-tor
Abby
Abc
Abcs
Abc's
ab-di-ca-ble
ab-di-cate
ab-di-ca-tion
ab-di-ca-tor
ab-do-men
ab-dom-i-nal
ab-dom-i-nal-ly
ab-dom-i-nous
ab-duce
ab-du-cent
ab-duct
ab-duc-tion
ab-duc-tor
abeam
abe-ce-dar-i-an
abed
#create word3
Abel
abele
abel-mosk
ab-er-rance
ab-er-ran-cy
ab-er-rant
ab-er-rant-ly
ab-er-ra-tion
ab-er-ra-tion-al
abet
abet-ment
abet-ted
abet-ter
abet-ting
abet-tor
abey-ance
abey-ant
abhominable
ab-hor
ab-horred
ab-hor-rence
ab-hor-rent
ab-hor-rent-ly
ab-hor-rer
ab-hor-ring
Abib
abid-ance
abide
abid-ed
abid-er
abid-ing
Abigail
ab-i-gail
abil-i-ty
abio-gen-e-ses
abio-gen-e-sis
abio-ge-net-ic
abio-ge-net-i-cal
abio-ge-net-i-cal-ly
abi-og-e-nist
#user
pr word* >X1
#cmp X1 neat
#log
#next
3.1f 10
iL3.1f } )#print
In this directory there are two files whose names
begin with "r". Copy them onto a new file called
"combine". Type "ready" when you're done.
#create ref
Now is the tuime
#create ref1
for all good men
#create X1
Now is the tuime
for all good men
#user
#cmp X1 combine
#log
#next
3.1g 10
-L3.1g b| #print
This exercise combines several things you've learned already.
In this directory is a file containing a list of words.
Collect all of the words that contain "ly" into a file
called "lywords". (What program does that?)
Then use "pr" to make another file called "neatly"
that contains the list of words printed in one column.
Type "ready" when you have made both files.
#create words
ampersand
amphetamine
amphiarthrosis
amphibia
amphibian
amphibiotic
amphibious
amphibiously
amphibiousness
amphibole
amphibolite
amphibolitic
amphibology
amphibrach
amphibrachic
amphictyonic
amphictyony
amphidiploid
amphidiploidy
amphimacer
amphimictic
amphimictically
amphimixis
Amphion
amphioxus
amphiploid
amphiploidy
amphipod
amphiprostyle
amphiprostyle
amphisbaena
amphisbaenic
amphistylar
amphitheater
amphitheatric
amphitheatrical
amphitheatrically
Amphitrite
amphitropous
Amphitryon
amphora
amphorae
amphoras
amphoteric
ample
ampleness
amplexicaul
amplidyne
amplification
amplifier
amplify
amplitude
amply
ampoule
ampul
ampulla
ampullae
ampullar
amputate
amputation
amputator
amputee
amtrac
amtrack
amuck
amulet
amuse
amusement
amuser
amusing
amusingly
amusive
Amy
amygdalin
amygdaloid
amygdaloidal
amyl
amylaceous
amylase
amyloid
amyloidal
amylolysis
amylolytic
amylopsin
amylose
amylum
amyotonia
an
an'
ana
an'a
anabaptism
Anabaptist
anabases
anabasis
anabatic
anabiosis
anabiotic
anabolic
anabolism
anabolite
anabolitic
anachronic
anachronism
anachronistic
anachronistically
anachronous
anachronously
anaclitic
anacolutha
anacoluthic
anacoluthically
anacoluthon
anacoluthons
anaconda
Anacreontic
anacreontic
anacrusis
anaculture
anadem
anadiplosis
anadromous
anaemia
anaerobe
anaerobic
anaerobically
anaesthesia
anaesthetic
anaglyph
anaglyphic
anagoge
anagogic
anagogical
anagogically
anagogy
anagram
anagrammatic
anagrammatical
anagrammatically
anagrammatize
anagrammed
anagramming
anal
analcime
analcite
analects
analemma
analeptic
analgesia
analgesic
analgetic
#user
grep ly words >X1
pr lywords >X2
cmp -s X1 lywords && cmp -s X2 neatly
#log
#next
4.1a 10
L4.1a m#print
You have already had some practice in using ">" to capture
the output of a program. In much the same way, it
is possible to arrange for a program to take its input not
from the terminal but from a file.
Most UNIX programs are written so that they will read either
the terminal or from a list of filenames.
To have a program read from a file instead of the terminal,
use the "<", like this:
pr <file
As a simple experiment, determine if
pr <file
is absolutely identical to
pr file
Answer yes or no.
#create junk
you can use this file to play with.
#copyin
#user
#uncopyin
#match no
#log
#next
4.1b 10
4.2a 5
wL4.1b _#print
Is there a difference between
grep the memo[12]
and
cat memo[12] >temp
grep the <temp
Answer yes or no.
If you want to experiment, there are two files named "memo1" and
"memo2" in this directory.
#create memo1
There is not room enough in the leaves to hold all the food
that plants make. Much of the food has to be stored in other parts
of the plant.
We eat the parts of plants where the most food is stored. The
carrot plant stores food in its roots. We eat the roots of carrots.
The celery plant stores food in its leaf stalks. They are the parts
we eat. Many kinds of plants store food in their fruits. We eat
the fruits of these plants to get the stored food in them.
Some kinds of plants have ways of protecting their stored food.
#create memo2
Goldfish grow very slowly in an aquarium. They grow so slowly
that it is hard to know that they grow at all. If they are kept
outdoors in a pool, they grow much faster and they grow much larger,
too. Sometimes they grow to be more than a foot long in an outdoor
pool.
When goldfish are kept in an aquarium they often do not live very
long. Sometimes they die in a few weeks, but they may live as long
as ten years. Some people have kept goldfish in an outdoor pool for
thirty years.
There are many different colors of goldfish.
#copyin
#user
#uncopyin
#match yes
#log
#next
4.1c 10
L4.1c q e#print
There are two files called "story1" and "story2" in
this directory. Collect the outputs of
grep the story[12]
and
cat story[12] >temp
grep the <temp
on two files called "the1" and "the2". Then
run "diff" on "the1" and "the2", and
collect the differences on a file called "difference".
Type "ready" when you have finished all of this.
#create story1
Some animals have six feet. These animals are insects.
Insects are little animals. Insects creep with their six feet.
Many insects have wings, too.
Ants are insects. Many ants live together. They live in ant
hills. Many ants travel together. Ants creep on their six feet.
Ants creep fast. They creep around on the ground. They creep in
and out of ant hills. They creep up and down plants. They creep
into houses.
Some ants have wings. They do not have wings all the time.
They grow wings to fly away. They fly away to find new homes.
Then they lose their wings.
#create story2
"Will there be baby robins soon?" asked Bill. "We will see,"
said Miss Fox. Joan said, "we have looked and looked. I think
there will be no baby birds." Barbara said, "It takes many days.
The eggs need to be warm all the time. The mother bird warms them."
Bill said, "The father bird helps, too." Joan said, "I guess I did
not think. There may be baby birds after all."
One day Carl called, "Come and look. I see four baby birds in
the nest." All the children ran to look. "But they are not pretty,"
Joan said. Bill said, "Joan is right."
#user
cat story[12] >X1
grep the <X1 >X2
grep the story[12] >X1
diff X1 X2 >X3
#cmp X3 difference
#log
#next
4.1d 10
bL4.1d y #print
Unix has several rather simple programs that are useful
in their own right and as building blocks in more complicated
operations. One of the most frequently used is "wc",
which counts lines, words, and characters in files.
If you say
wc file
or
wc <file
wc will print three numbers: the number of
lines, words and characters in the file.
(Some systems have an obsolete version of "wc" that
doesn't count the characters.)
If there is more than one file, as in
wc file1 file2 file3 file4
then wc will list the counts for each file separately,
and the total.
What is the total number of words
in the two files whose names begin with "memo"?
Type "answer N", where N is the number of words.
#create memo1
It has been mentioned as one of the advantages to be expected
from the cooperation of the Senate, in the business
of appointments, that it would contribute to the
stability of the administration. The consent of that body
would be necessary to displace as well as to appoint. A
change of the Chief Magistrate, therefore, would not occasion
so violent or so general a revolution in the officers
of the government as might be expected if he were the
sole disposer of offices. Where a man in any station had
given satisfactory evidence of his fitness for it, a new
President would be restrained from attempting a change
in favor of a person more agreeable to him by the apprehension
that a discountenance of the Senate might frustrate
the attempt, and bring some degree of discredit
upon himself. Those who can best estimate the value of
a steady administration will be most disposed to prize a
provision which connects the official existence of public
men with the approbation or disapprobation of that body
which, from the greater permanency of its own composition,
will in all probability be less subject to inconstancy
than any other member of the government.
To this union of the Senate with the President, in the
article of appointments, it has in some cases been suggested
that it would serve to give the President an undue
influence over the Senate, and in others that it would
have an opposite tendency - a strong proof that neither
suggestion is true.
To state the first in its proper form is to refute it. It
amounts to this: the President would have an improper
influence over the Senate, because the Senate would
have the power of restraining him. This is an absurdity in
terms. It cannot admit of a doubt that the entire power
of appointment would enable him much more effectually
to establish a dangerous empire over that body than a
mere power of nomination subject to their control.
Let us take a view of the converse of the proposition:
"the Senate would influence the executive." As I have
had occasion to remark in several other instances, the indistinctness
of the objection forbids a precise answer. In
what manner is this influence to be exerted? In relation
to what objects? The power of influencing a person, in
the sense in which it is here used, must imply a power of
conferring a benefit upon him. How could the Senate
confer a benefit upon the President by the manner of employing
their right of negative upon his nominations? If it
be said they might sometimes gratify him by an acquiescence
in a favorite choice, when public motives might dictate a
different conduct, I answer that the instances in which the
President could be personally interested in the result would
be too few to admit of his being materially affected by the
#create memo2
compliances of the Senate. Besides this, it is evident that
the POWER which can originate the disposition of honors
and emoluments is more likely to attract than to be attracted
by the POWER which can merely obstruct their
course. If by influencing the President be want restraining
him, this is precisely what must have been intended.
And it has been shown that the restraint would be salutary,
at the same time that it would not be such as to
destroy a single advantage to be looked for from the uncontrolled
agency of that magistrate. The right of nomination
would produce all the good, without the ill.
Upon a comparison of the plan for the appointment of
the officers of the proposed government with that which
is established by the constitution of this State, a decided
preference must be given to the former. In that plan the
power of nomination is unequivocally vested in the executive.
And as there would be a necessity for submitting
each nomination to the judgment of an entire branch of
the legislature, the circumstances attending an appointment,
from the mode of conducting it, would naturally
become matters of notoriety, and the public would
be at no loss to determine what part had been performed
by the different actors. The blame of a bad nomination
would fall upon the President singly and absolutely. The
censure of rejecting a good one would lie entirely at the
door of the senate, aggravated by the consideration
of their having counteracted the good intentions of the
executive. If an ill appointment should be made, the executive,
for nominating, and the Senate, for approving,
would participate, though in different degrees, in the
opprobrium and disgrace.
The reverse of all this characterizes the manner of appointment
in this State. The council of appointment consists
of from three to five persons, of whom the governor
is always one. This small body, shut up in a private
apartment, impenetrable to the public eye, proceed to the
execution of the trust committed to them. It is known
that the governor claims the right of nomination upon
the strength of some ambiguous expressions in the Constitution;
but it is not known to what extent, or in what
manner he exercises it; nor upon what occasions he is
contradicted or opposed. The censure of a bad appointment,
on account of the uncertainty of its author and for
want of a determinate object, has neither poignancy nor
duration. And while an unbounded field for cabal and intrigue
lies open, all idea of responsibility is lost. The
most that the public can know is that the governor
claims the right of nomination; that two out of the inconsiderable
number of four men can too often be managed
without much difficulty; that if some of the members of a
#copyin
#user
#uncopyin
#match 949
#log
#next
4.1e 10
dL4.1e e#print
How many lines total are there in the two files called
"chema" and "chemb" in this directory? Use "wc".
Type "answer N", where N is the total number of lines.
#create chema
The baker said, "Now I shall put just the right amounts of water and
yeast with the flour that is in the mixer. Flour, water, and yeast
together make the sponge. Making sponge is the first step in making
bread."
The baker closed the mixer. Inside the machine, the flour and
yeast and water went around and around until they were well mixed.
Then the baker opened the mixer and the sponge dropped into a greased
tub called a trough.
The baker pushed the trough into a warm room to let the sponge
rise. It looked like dough, but it did not as yet have everything
in it.
#create chemb
Wash the blackboard. Watch it dry. The water goes into the air.
When water goes into the air it evaporates.
Tie a damp cloth to one end of a stick. Tie a bottle to the
other end. Put water in the bottle until the stick is level. Watch
the stick for a few minutes. It does not stay level.
Water goes into the air when it evaporates. It changes into
water vapor. You cannot see water vapor, but it is in the air all
around you.
Cut a hole in the bottom of a cardboard box. Hold the box
against a cold window and blow into the hole.
#copyin
#user
#uncopyin
#match 21
#log
#next
4.1f 10
eL4.1f #print
Another useful command is "tail", which will print the last
10 lines of a file. This is handy when you want to see how
far something got before it stopped, or what the last thing
in a file is. To use "tail", all you need to say is
tail file
What is the first word on the next to last line of the file
called "Ref" in this directory.
Type "answer WORD", where WORD is the word you found.
#create Ref
Now Abraham Lincoln was master of the White House. But he was
President of only part of the United States. For the Southern
States has taken down the Star-Spangled Banner and raised the flag
of the Confederacy in its stead. Sad and silent, Lincoln gazed
through his spyglass at the Confederate flag that fluttered in the
wind on the other side of the Potomac River in Virginia. He pondered
how to get the Southern States back into the Union. He needed
quiet to think what to do. But from morning till night the White
House was crowded with people seeking his help.
About a hundred and fifty years after the pilgrims settled in
this country, a young hunter picked up his gun. He tossed it onto
his shoulder and followed a buffalo trail across the mountains into
what is now Kentucky.
His name was Daniel Boone.
He found wild country. There were no settlers, no roads. Indians
hunted in the woods for food. The country was beautiful and dangerous.
But here was rich, free land -- miles and miles of it.
Many settlers, besides the Pilgrims, had come to the shores of
America. But they had stayed on the safe land between the sea and
the mountains.
Columbus discovered America in 1492. Later, other explorers
visited the new land. They told people in Europe of the forests,
furs, and fish they found. Many Europeans decided to settle in
this wonderful land. But some of the first settlers starved to
death during the hard winters. Others lived to build settlements
or colonies for their mother countries. Colonial America was
beginning. In 1607, three ships brought men from England to what
is now Jamestown, Virginia. They were looking for gold.
The leader, Captain John Smith, taught the men to build houses
of stakes and branches. They plastered the walls of the houses with
mud.
#copyin
#user
#uncopyin
#match of
#log
#next
4.1g 10
L4.1g _ #print
By default, "tail" prints the last 10 lines of its input.
You can change this default amount by specifying a different
amount as an optional argument. For example,
tail -5 file
prints the last 5 lines of "file".
Collect the last line of the file "Ref" in a new file
called "last". Type "ready" when you have finished.
(By the way, there is a limit to how big the number can be,
but it's usually at least 60 or 70 lines of normal text.)
#create Ref
About a hundred and fifty years after the pilgrims settled in
Columbus discovered America in 1492. Later, other explorers
He found wild country. There were no settlers, no roads. Indians
His name was Daniel Boone.
Many settlers, besides the Pilgrims, had come to the shores of
Now Abraham Lincoln was master of the White House. But he was
The leader, Captain John Smith, taught the men to build houses
America. But they had stayed on the safe land between the sea and
But here was rich, free land -- miles and miles of it.
House was crowded with people seeking his help.
President of only part of the United States. For the Southern
States has taken down the Star-Spangled Banner and raised the flag
beginning. In 1607, three ships brought men from England to what
death during the hard winters. Others lived to build settlements
furs, and fish they found. Many Europeans decided to settle in
his shoulder and followed a buffalo trail across the mountains into
how to get the Southern States back into the Union. He needed
hunted in the woods for food. The country was beautiful and dangerous.
is now Jamestown, Virginia. They were looking for gold.
mud.
of stakes and branches. They plastered the walls of the houses with
of the Confederacy in its stead. Sad and silent, Lincoln gazed
or colonies for their mother countries. Colonial America was
quiet to think what to do. But from morning till night the White
the mountains.
this country, a young hunter picked up his gun. He tossed it onto
this wonderful land. But some of the first settlers starved to
through his spyglass at the Confederate flag that fluttered in the
visited the new land. They told people in Europe of the forests,
what is now Kentucky.
wind on the other side of the Potomac River in Virginia. He pondered
#create X1
wind on the other side of the Potomac River in Virginia. He pondered
#user
#cmp X1 last
#log
#next
5.1a 10
L4.2a #print
Is the command
cat <file
identical to
cat file
Answer yes or no.
#copyin
#user
#uncopyin
#match yes
#log
#next
4.1b 10
L5.1a D K#print
If you think back over some of the exercises you've done
so far in this course, they have involved collecting the
output of one program (like "cat" or "grep" or "ls") in
a file, then using that file as the input to another
program, like "pr" or "wc" or "grep".
For example, you could use "ls" and "wc" to _____count
the number of files in a directory. Do that now,
then type "answer N", where N is the number of files.
#create X2
#create X1
#create this
#create stuff
#create foo
#copyin
#user
#uncopyin
ls | %s/../lcount >X1
tail -1 .copy >X2
#cmp X1 X2
#log
#next
5.1b 10
hL5.1b #print
It seems silly to use a temporary file when all that's really
needed is to take the output from one program like "ls",
and pass it directly to the input of another, like "wc".
One of the original contributions of Unix is a clean
way to do this, called a "pipe". You can connect two
programs with a pipe like this:
ls | wc
and the output of the first program goes into the input of
the second without any intervening file.
Try this pair of commands in a pipeline.
Try an ordinary "ls" command too, to verify that you
got the right answer. Then type "ready".
#create X1
#copyin
#user
#uncopyin
grep 'ls *| *wc' .copy >/dev/null
#log
#next
5.1c
L5.1c
#print
Another use for pipes is to replace a command sequence that we
did earlier with "cat", "pr" and a temporary file. If you have
a bunch of small files, using "pr" on them directly wastes
paper, since each file takes a page. You could say
cat memo* >temp
pr temp
rm temp
but this is a nuisance (and the output will
have the title "temp" on each page). So use
a pipe instead.
In this directory there are some files whose
names begin with "word". Use "cat", "pr" and a pipe
to print them, then type "ready".
#create word1
now
is
the
time
for
all
#create word2
good
men
to
come
to
the
aid
#create word3
of
their
party.
#copyin
#user
#uncopyin
grep 'cat word.*| *pr' <.copy >/dev/null
#log
#next
5.1d 10
L5.1d $ ^#print
How many lines of output does the command
cat word* | pr
produce, as computed by "wc"?
Type "answer N", where N is the number of lines.
(Try to use a pipe, not a temporary file.)
#create word1
Now
is
the
time
#create word2
for
all
good
men
#create word3
to
come
to
the
aid
of
their
party
#copyin
#user
#uncopyin
#match 66
#log
#next
5.1e 10
L5.1e K#print
Use "ls", "pr" and a pipe to make a neat list of the files
in this directory, sorted by time of last change.
Do not use a temporary file.
Type "ready" when you are done.
#create x1
adfasdfasdfaf
#create junk
qerqer
#create foo
fofofofofo
#copyin
#user
#uncopyin
grep 'ls -[l]*t.*| *pr' <.copy >/dev/null
#log
#next
6.1a 10
#L6.1a L#print
Of course it is still possible to use files with "<" and ">"
to supply input to one end of a pipeline and to
collect the output from the other end.
In this directory are two files whose names begin
with "bio". Collect the last 15 lines of these two files
(combined) in a file called "last", then type "ready".
#create bio1
Roughly speaking, your eye is made of three balls, or layers,
fitted tightly one inside the other. the tough white outermost
layer's function is to protect the others. the middle layer gives
the front of your eye its brown, gray, or blue color. The inside
of this layer is dark and full of tiny blood vessels. The innermost
layer, called the retina, is made of very special nerve cells that
are sensitive to light and color. A nerve cord connects the retina
of each eye to your brain.
The front of your eye's two outer layers (the cornea) is clear,
or open, to let light enter.
#create bio2
We do not know when life began on the earth, and it seems likely
that the answer to this question will remain forever hidden from us.
What we do know is that it was some 500 million years ago when the
plants and animals of early geologic history had reached a stage of
development where they produced hard parts capable of being preserved
as fossils.
At this distant date there seemingly was no land life; all life
was in the sea. Moreover, there were no vertebrates, or backboned
animals, living -- at least none of sufficient complexity that they
left hard structures to be preserved in the form of fossils.
#user
cat bio* | tail -15 >X1
#cmp X1 last
#log
#next
6.1b 10
L6.1b : [#print
Several of the programs we have been using as examples,
such as "grep" and "wc", have the property that when
you use file names with them, the output includes
the file names. For example, if you say
grep pattern file1 file2 file3
each line that contains "pattern" is printed out
with "file1:" or whatever in front of it.
Sometimes you would love to get rid of that file name, since
you don't care a bit where the line came from,
and the file name clutters up the output.
One thing is to use "cat" to collect the files, and
pipe into "grep"; in that case "grep" doesn't mention
any file name because there isn't one.
In this directory there are several files whose names end
in ".x". Use a pipeline of "cat" and "grep" to print all the lines
that contain the letters "ion", without any identifying filenames.
Type "ready" when you're done.
#create 0x
ion, but this one is in the wrong file!
#create 1.x
o
o'
oaf
oafish
oafishly
oafishness
oak
oaken
oaks
oakum
oar
oared
oarfish
oarlock
oarsman
oases
oasis
oat
oatcake
oaten
oath
oaths
oatmeal
obbligati
obbligato
obbligatos
obconic
obcordate
obduracy
obdurate
#create 2.x
obdurately
obdurateness
obeah
obedience
obedient
obediently
obeisance
obeisant
obeli
obelisk
obelize
obelus
obese
obesity
obey
obeyer
obfuscate
obfuscation
obfuscatory
obi
obit
obituary
object
objectification
objectify
objection
objectionable
objectionableness
objectionably
objective
#create 3.x
objectively
objectiveness
objectivism
objectivist
objectivistic
objectivity
objectless
objector
objurgate
objurgation
objurgatory
oblanceolate
oblast
oblate
oblate
oblateness
oblation
obligate
obligately
obligation
obligatorily
obligatory
oblige
obligee
obliger
obliging
obligingly
obligingness
obligor
oblique
obliquely
obliqueness
obliquity
obliterate
#copyout
#user
#uncopyout
grep ion <.ocopy >X1
cat *.x | grep ion >X2
#cmp X1 X2
#log
#next
6.1c
oL6.1c D +#print
In much the same way that you used "cat" and a pipe to
get rid of the file names from the output of "grep",
you can use "cat" and a pipe to get rid of the sub-totals
from "wc", if you so desire.
What is the total number of lines in the files in
this directory whose names begin with capital letters?
Type "answer N", where N is the number of lines.
#create X1
just to make sure.
#create Stuff
this has some more.
#create Junk
asdfadfasdfasdfasdfasf
#copyin
#user
#uncopyin
cat [A-Z]* | %s/../lcount >x1
tail -1 .copy >x2
#cmp x1 x2
#log
#next
6.1d
cL6.1d 7
#print
How many of the lines in the files "bio*" and "chem*"
contain the letters "the"? Type "answer N", where
N is the number of lines.
#create bio1
Roughly speaking, your eye is made of three balls, or layers,
fitted tightly one inside the other. the tough white outermost
layer's function is to protect the others. the middle layer gives
the front of your eye its brown, gray, or blue color. The inside
of this layer is dark and full of tiny blood vessels. The innermost
layer, called the retina, is made of very special nerve cells that
are sensitive to light and color. A nerve cord connects the retina
of each eye to your brain.
The front of your eye's two outer layers (the cornea) is clear,
or open, to let light enter.
#create bio2
We do not know when life began on the earth, and it seems likely
that the answer to this question will remain forever hidden from us.
What we do know is that it was some 500 million years ago when the
plants and animals of early geologic history had reached a stage of
development where they produced hard parts capable of being preserved
as fossils.
At this distant date there seemingly was no land life; all life
was in the sea. Moreover, there were no vertebrates, or backboned
animals, living -- at least none of sufficient complexity that they
left hard structures to be preserved in the form of fossils.
#create chema
The baker said, "Now I shall put just the right amounts of water and
yeast with the flour that is in the mixer. Flour, water, and yeast
together make the sponge. Making sponge is the first step in making
bread."
The baker closed the mixer. Inside the machine, the flour and
yeast and water went around and around until they were well mixed.
Then the baker opened the mixer and the sponge dropped into a greased
tub called a trough.
The baker pushed the trough into a warm room to let the sponge
rise. It looked like dough, but it did not as yet have everything
in it.
#create chemb
Wash the blackboard. Watch it dry. The water goes into the air.
When water goes into the air it evaporates.
Tie a damp cloth to one end of a stick. Tie a bottle to the
other end. Put water in the bottle until the stick is level. Watch
the stick for a few minutes. It does not stay level.
Water goes into the air when it evaporates. It changes into
water vapor. You cannot see water vapor, but it is in the air all
around you.
Cut a hold in the bottom of a cardboard box. Hold the box
against a cold window and blow into the hole.
#copyin
#user
#uncopyin
#match 30
#log
#next
6.1e
L6.1e J F#print
By the way, you can also use "grep" to print out ___all ___but
those lines that contain occurrences of a pattern:
grep -v pat files...
prints all the lines in files... that don't contain
any "pat".
How many of the lines in "bio*" don't contain "the"?
Type "answer N", where N is the number of lines.
#create bio1
Roughly speaking, your eye is made of three balls, or layers,
fitted tightly one inside the other. the tough white outermost
layer's function is to protect the others. the middle layer gives
the front of your eye its brown, gray, or blue color. The inside
of this layer is dark and full of tiny blood vessels. The innermost
layer, called the retina, is made of very special nerve cells that
are sensitive to light and color. A nerve cord connects the retina
of each eye to your brain.
The front of your eye's two outer layers (the cornea) is clear,
or open, to let light enter.
#create bio2
We do not know when life began on the earth, and it seems likely
that the answer to this question will remain forever hidden from us.
What we do know is that it was some 500 million years ago when the
plants and animals of early geologic history had reached a stage of
development where they produced hard parts capable of being preserved
as fossils.
At this distant date there seemingly was no land life; all life
was in the sea. Moreover, there were no vertebrates, or backboned
animals, living -- at least none of sufficient complexity that they
left hard structures to be preserved in the form of fossils.
#copyin
#user
#uncopyin
#match 6
#log
#next
7.1a 10
6.2e 5
L6.2e S #print
How many words in the file "o" do not contain a
slash "/"? Type "answer N", where N is the number of words.
#create o
o
o'
oaf
oaf/ish
oaf/ish/ly
oaf/ish/ness
oak
oak/en
oaks
oa/kum
oar
oared
oar/fish
oar/lock
oars/man
oa/ses
oa/sis
oat
oat/cake
oat/en
oath
oaths
oat/meal
ob/bli/ga/ti
ob/bli/ga/to
obbligatos
ob/con/ic
ob/cor/date
ob/du/ra/cy
ob/du/rate
ob/du/rate/ly
ob/du/rate/ness
obe/ah
obe/di/ence
obe/di/ent
obe/di/ent/ly
obei/sance
obei/sant
ob/e/li
ob/e/lisk
ob/e/lize
ob/e/lus
obese
obe/si/ty
obey
obey/er
ob/fus/cate
ob/fus/ca/tion
ob/fus/ca/to/ry
obi
obit
obit/u/ary
ob/ject
ob/jec/ti/fi/ca/tion
ob/jec/ti/fy
ob/jec/tion
ob/jec/tion/able
ob/jec/tion/able/ness
ob/jec/tion/ably
ob/jec/tive
ob/jec/tive/ly
ob/jec/tive/ness
ob/jec/tiv/ism
ob/jec/tiv/ist
ob/jec/tiv/is/tic
ob/jec/tiv/i/ty
ob/ject/less
ob/jec/tor
ob/jur/gate
ob/jur/ga/tion
ob/jur/ga/to/ry
ob/lan/ceo/late
oblast
ob/late
oblate
oblate/ness
obla/tion
ob/li/gate
ob/li/gate/ly
ob/li/ga/tion
oblig/a/to/ri/ly
oblig/a/to/ry
oblige
ob/li/gee
oblig/er
oblig/ing
oblig/ing/ly
oblig/ing/ness
ob/li/gor
oblique
oblique/ly
oblique/ness
obliq/ui/ty
oblit/er/ate
oblit/er/a/tion
#copyin
#user
#uncopyin
#match 19
#log
#next
7.1a
tL7.1a W #print
Do you think that you have learned anything
from this script?
Answer yes or no.
#copyin
#user
#uncopyin
#match yes
#log
o