V3/usr/man/man1/if.1

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NAME		if --  conditional command
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SYNOPSIS	if__ expr command [ arg918 ... ]
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DESCRIPTION	if__
evaluates the expression expr____, and if its value is true____,
executes the given command_______ with the given arguments.

The following primitives are used to construct
the expr____:

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-r__ file
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true if the file exists and is readable.

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-w__ file
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true if the file exists and is writable

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s1 =_ s2
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true if the strings s1__ and s2__ are equal.

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s1 !=__ s2
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true if the strings s1__ and s2__ are not equal.

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These primaries may be combined with the
following operators:

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!_
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unary negation operator

-a__
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binary and___ operator

-o__
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binary or__ operator

(_ expr )_
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parentheses for grouping.

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-a__ has higher precedence than -o__.
Notice that all the operators and flags are separate
arguments to if__ and hence must be surrounded by spaces.
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FILES		--
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SEE ALSO	sh(I)
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DIAGNOSTICS	"if error",
if the expression has the wrong syntax;
"command not found."
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BUGS		--