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Diffstat (limited to 'doc_src/function.txt')
| -rw-r--r-- | doc_src/function.txt | 104 |
1 files changed, 68 insertions, 36 deletions
diff --git a/doc_src/function.txt b/doc_src/function.txt index 8d8e4519..1f9fb47d 100644 --- a/doc_src/function.txt +++ b/doc_src/function.txt @@ -1,61 +1,93 @@ \section function function - create a function \subsection function-synopsis Synopsis - <code>function [OPTIONS] NAME; BODY; end </code> +\fish{synopsis} +function [OPTIONS] NAME; BODY; end +\endfish \subsection function-description Description -\c function creates a new function \c NAME with the body <code>BODY</code>. +`function` creates a new function `NAME` with the body `BODY`. -A function is a list of commands that will be executed when the name of the -function is given as a command. +A function is a list of commands that will be executed when the name of the function is given as a command. The following options are available: -- <code>-a NAMES</code> or <code>--argument-names NAMES</code> assigns the value of successive command-line arguments to the names given in NAMES. -- <code>-d DESCRIPTION</code> or \c --description=DESCRIPTION is a description of what the function does, suitable as a completion description. -- <code>-e</code> or <code>--on-event EVENT_NAME</code> tells fish to run this function when the specified named event is emitted. Fish internally generates named events e.g. when showing the prompt. -- <code>-j PID</code> or <code> --on-job-exit PID</code> tells fish to run this function when the job with group ID PID exits. Instead of PID, the string 'caller' can be specified. This is only legal when in a command substitution, and will result in the handler being triggered by the exit of the job which created this command substitution. -- <code>-p PID</code> or <code> --on-process-exit PID</code> tells fish to run this function when the fish child process with process ID PID exits. -- <code>-s</code> or <code>--on-signal SIGSPEC</code> tells fish to run this function when the signal SIGSPEC is delivered. SIGSPEC can be a signal number, or the signal name, such as SIGHUP (or just HUP). -- \c -S or \c --no-scope-shadowing allows the function to access the variables of calling functions. Normally, any variables inside the function that have the same name as variables from the calling function are "shadowed", and their contents is independent of the calling function. -- <code>-v</code> or <code>--on-variable VARIABLE_NAME</code> tells fish to run this function when the variable VARIABLE_NAME changes value. +- `-a NAMES` or `--argument-names NAMES` assigns the value of successive command-line arguments to the names given in NAMES. -If the user enters any additional arguments after the function, they -are inserted into the environment <a href="index.html#variables-arrays">variable array</a> -<code>$argv</code>. If the \c --argument-names option is provided, the arguments are -also assigned to names specified in that option. +- `-d DESCRIPTION` or `--description=DESCRIPTION` is a description of what the function does, suitable as a completion description. + +- `-w WRAPPED_COMMAND` or `--wraps=WRAPPED_COMMAND` causes the function to inherit completions from the given wrapped command. See the documentation for <a href="#complete">`complete`</a> for more information. + +- `-e` or `--on-event EVENT_NAME` tells fish to run this function when the specified named event is emitted. Fish internally generates named events e.g. when showing the prompt. + +- `-v` or `--on-variable VARIABLE_NAME` tells fish to run this function when the variable VARIABLE_NAME changes value. + +- `-j PGID` or `--on-job-exit PGID` tells fish to run this function when the job with group ID PGID exits. Instead of PGID, the string 'caller' can be specified. This is only legal when in a command substitution, and will result in the handler being triggered by the exit of the job which created this command substitution. + +- `-p PID` or `--on-process-exit PID` tells fish to run this function when the fish child process with process ID PID exits. + +- `-s` or `--on-signal SIGSPEC` tells fish to run this function when the signal SIGSPEC is delivered. SIGSPEC can be a signal number, or the signal name, such as SIGHUP (or just HUP). + +- `-S` or `--no-scope-shadowing` allows the function to access the variables of calling functions. Normally, any variables inside the function that have the same name as variables from the calling function are "shadowed", and their contents is independent of the calling function. + +- `-V` or `--inherit-variable NAME` snapshots the value of the variable `NAME` and defines a local variable with that same name and value when the function is executed. + +If the user enters any additional arguments after the function, they are inserted into the environment <a href="index.html#variables-arrays">variable array</a> `$argv`. If the `--argument-names` option is provided, the arguments are also assigned to names specified in that option. By using one of the event handler switches, a function can be made to run automatically at specific events. The user may generate new events using the <a href="#emit">emit</a> builtin. Fish generates the following named events: -- \c fish_prompt, which is emitted whenever a new fish prompt is about to be displayed. -- \c fish_command_not_found, which is emitted whenever a command lookup failed. +- `fish_prompt`, which is emitted whenever a new fish prompt is about to be displayed. + +- `fish_command_not_found`, which is emitted whenever a command lookup failed. + +- `fish_preexec`, which is emitted right before executing an interactive command. The commandline is passed as the first parameter. + + Note: This event will be emitted even if the command is invalid. The commandline parameter includes the entire commandline verbatim, and may potentially include newlines. + +- `fish_postexec`, which is emitted right after executing an interactive command. The commandline is passed as the first parameter. + + Note: This event will be emitted even if the command is invalid. The commandline parameter includes the entire commandline verbatim, and may potentially include newlines. + \subsection function-example Example -<pre> +\fish function ll - ls -l $argv + ls -l $argv end -</pre> +\endfish -will run the \c ls command, using the \c -l option, while passing on any additional files and switches to \c ls. +will run the `ls` command, using the `-l` option, while passing on any additional files and switches to `ls`. -<pre> +\fish function mkdir -d "Create a directory and set CWD" - command mkdir $argv - if test $status = 0 - switch $argv[(count $argv)] - case '-*' - - case '*' - cd $argv[(count $argv)] - return - end - end + command mkdir $argv + if test $status = 0 + switch $argv[(count $argv)] + case '-*' + + case '*' + cd $argv[(count $argv)] + return + end + end +end +\endfish + +This will run the `mkdir` command, and if it is successful, change the current working directory to the one just created. + +\fish +function notify + set -l job (jobs -l -g) + or begin; echo "There are no jobs" >&2; return 1; end + + function _notify_job_$job --on-job-exit $job --inherit-variable job + echo -n \a # beep + functions -e _notify_job_$job + end end -</pre> +\endfish -will run the mkdir command, and if it is successful, change the -current working directory to the one just created. +This will beep when the most recent job completes. |