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https://github.com/fish-shell/fish-shell
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41 lines
1.5 KiB
Text
41 lines
1.5 KiB
Text
\section if if - conditionally execute a command
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\subsection if-synopsis Synopsis
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\fish{synopsis}
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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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\endfish
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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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In order to use the exit status of multiple commands as the condition of an if block, use <a href="#begin">`begin; ...; end`</a> and the short circuit commands <a href="commands.html#and">`and`</a> and <a href="commands.html#or">`or`</a>.
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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 begin test -f foo.txt
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and test -r foo.txt
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end
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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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