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42 lines
1.3 KiB
ReStructuredText
42 lines
1.3 KiB
ReStructuredText
if - conditionally execute a command
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==========================================
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Synopsis
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--------
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if CONDITION; COMMANDS_TRUE...;
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[else if CONDITION2; COMMANDS_TRUE2...;]
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[else; COMMANDS_FALSE...;]
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end
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\subsection if-description Description
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`if` will execute the command `CONDITION`. If the condition's exit status is 0, the commands `COMMANDS_TRUE` will execute. If the exit status is not 0 and `else` is given, `COMMANDS_FALSE` will be executed.
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You can use <a href="#and">`and`</a> or <a href="#or">`or`</a> in the condition. See the second example below.
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The exit status of the last foreground command to exit can always be accessed using the <a href="index.html#variables-status">$status</a> variable.
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\subsection if-example Example
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The following code will print `foo.txt exists` if the file foo.txt exists and is a regular file, otherwise it will print `bar.txt exists` if the file bar.txt exists and is a regular file, otherwise it will print `foo.txt and bar.txt do not exist`.
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\fish
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if test -f foo.txt
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echo foo.txt exists
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else if test -f bar.txt
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echo bar.txt exists
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else
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echo foo.txt and bar.txt do not exist
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end
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\endfish
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The following code will print "foo.txt exists and is readable" if foo.txt is a regular file and readable
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\fish
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if test -f foo.txt
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and test -r foo.txt
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echo "foo.txt exists and is readable"
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end
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\endfish
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