mirror of
https://github.com/fish-shell/fish-shell
synced 2024-12-26 21:03:12 +00:00
222 lines
9 KiB
ReStructuredText
222 lines
9 KiB
ReStructuredText
.. _cmd-set:
|
|
|
|
set - display and change shell variables
|
|
========================================
|
|
|
|
Synopsis
|
|
--------
|
|
|
|
.. synopsis::
|
|
|
|
set
|
|
set (-f | --function) (-l | --local) (-g | --global) (-U | --universal) [--no-event]
|
|
set [-Uflg] NAME [VALUE ...]
|
|
set [-Uflg] NAME[[INDEX ...]] [VALUE ...]
|
|
set (-x | --export) (-u | --unexport) [-Uflg] NAME [VALUE ...]
|
|
set (-a | --append) (-p | --prepend) [-Uflg] NAME VALUE ...
|
|
set (-q | --query) (-e | --erase) [-Uflg] [NAME][[INDEX]] ...]
|
|
set (-S | --show) (-L | --long) [NAME ...]
|
|
|
|
Description
|
|
-----------
|
|
|
|
``set`` manipulates :ref:`shell variables <variables>`.
|
|
|
|
If both *NAME* and *VALUE* are provided, ``set`` assigns any values to variable *NAME*.
|
|
Variables in fish are :ref:`lists <variables-lists>`, multiple values are allowed.
|
|
One or more variable *INDEX* can be specified including ranges (not for all options.)
|
|
|
|
If no *VALUE* is given, the variable will be set to the empty list.
|
|
|
|
If ``set`` is ran without arguments, it prints the names and values of all shell variables in sorted order.
|
|
Passing :ref:`scope <variables-scope>` or :ref:`export <variables-export>` flags allows filtering this to only matching variables, so ``set --local`` would only show local variables.
|
|
|
|
With ``--erase`` and optionally a scope flag ``set`` will erase the matching variable (or the variable of that name in the smallest possible scope).
|
|
|
|
With ``--show``, ``set`` will describe the given variable names, explaining how they have been defined - in which scope with which values and options.
|
|
|
|
The following options control variable scope:
|
|
|
|
**-U** or **--universal**
|
|
Sets a universal variable.
|
|
The variable will be immediately available to all the user's ``fish`` instances on the machine, and will be persisted across restarts of the shell.
|
|
|
|
**-f** or **--function**
|
|
Sets a variable scoped to the executing function.
|
|
It is erased when the function ends.
|
|
|
|
**-l** or **--local**
|
|
Sets a locally-scoped variable in this block.
|
|
It is erased when the block ends.
|
|
Outside of a block, this is the same as **--function**.
|
|
|
|
**-g** or **--global**
|
|
Sets a globally-scoped variable.
|
|
Global variables are available to all functions running in the same shell.
|
|
They can be modified or erased.
|
|
|
|
These options modify how variables operate:
|
|
|
|
**--export** or **-x**
|
|
Causes the specified shell variable to be exported to child processes (making it an "environment variable").
|
|
|
|
**--unexport** or **-u**
|
|
Causes the specified shell variable to NOT be exported to child processes.
|
|
|
|
**--path**
|
|
Treat specified variable as a :ref:`path variable <variables-path>`; variable will be split on colons (``:``) and will be displayed joined by colons when quoted (``echo "$PATH"``) or exported.
|
|
|
|
**--unpath**
|
|
Causes variable to no longer be treated as a :ref:`path variable <variables-path>`.
|
|
Note: variables ending in "PATH" are automatically path variables.
|
|
|
|
Further options:
|
|
|
|
**-a** or **--append** *NAME* *VALUE* ...
|
|
Appends *VALUES* to the current set of values for variable **NAME**.
|
|
Can be used with **--prepend** to both append and prepend at the same time.
|
|
This cannot be used when assigning to a variable slice.
|
|
|
|
**-p** or **--prepend** *NAME* *VALUE* ...
|
|
Prepends *VALUES* to the current set of values for variable **NAME**.
|
|
This can be used with **--append** to both append and prepend at the same time.
|
|
This cannot be used when assigning to a variable slice.
|
|
|
|
**-e** or **--erase** *NAME*\[*INDEX*\]
|
|
Causes the specified shell variables to be erased.
|
|
Supports erasing from multiple scopes at once.
|
|
Individual items in a variable at *INDEX* in brackets can be specified.
|
|
|
|
**-q** or **--query** *NAME*\[*INDEX*\]
|
|
Test if the specified variable names are defined.
|
|
If an *INDEX* is provided, check for items at that slot.
|
|
Does not output anything, but the shell status is set to the number of variables specified that were not defined, up to a maximum of 255.
|
|
If no variable was given, it also returns 255.
|
|
|
|
**-n** or **--names**
|
|
List only the names of all defined variables, not their value.
|
|
The names are guaranteed to be sorted.
|
|
|
|
**-S** or **--show**
|
|
Shows information about the given variables.
|
|
If no variable names are given then all variables are shown in sorted order.
|
|
It shows the scopes the given variables are set in, along with the values in each and whether or not it is exported.
|
|
No other flags can be used with this option.
|
|
|
|
**--no-event**
|
|
Don't generate a variable change event when setting or erasing a variable.
|
|
We recommend using this carefully because the event handlers are usually set up for a reason.
|
|
Possible uses include modifying the variable inside a variable handler.
|
|
|
|
**-L** or **--long**
|
|
Do not abbreviate long values when printing set variables.
|
|
|
|
**-h** or **--help**
|
|
Displays help about using this command.
|
|
|
|
If a variable is set to more than one value, the variable will be a list with the specified elements.
|
|
If a variable is set to zero elements, it will become a list with zero elements.
|
|
|
|
If the variable name is one or more list elements, such as ``PATH[1 3 7]``, only those list elements specified will be changed.
|
|
If you specify a negative index when expanding or assigning to a list variable, the index will be calculated from the end of the list.
|
|
For example, the index -1 means the last index of a list.
|
|
|
|
The scoping rules when creating or updating a variable are:
|
|
|
|
- Variables may be explicitly set as universal, global, function, or local.
|
|
Variables with the same name but in a different scope will not be changed.
|
|
|
|
- If the scope of a variable is not explicitly set *but a variable by that name has been previously defined*, the scope of the existing variable is used.
|
|
If the variable is already defined in multiple scopes, the variable with the narrowest scope will be updated.
|
|
|
|
- If a variable's scope is not explicitly set and there is no existing variable by that name, the variable will be local to the currently executing function.
|
|
Note that this is different from using the ``-l`` or ``--local`` flag, in which case the variable will be local to the most-inner currently executing block, while without them the variable will be local to the function as a whole.
|
|
If no function is executing, the variable will be set in the global scope.
|
|
|
|
|
|
The exporting rules when creating or updating a variable are identical to the scoping rules for variables:
|
|
|
|
- Variables may be explicitly set to either exported or not exported.
|
|
When an exported variable goes out of scope, it is unexported.
|
|
|
|
- If a variable is not explicitly set to be exported or not exported, but has been previously defined, the previous exporting rule for the variable is kept.
|
|
|
|
- If a variable is not explicitly set to be either exported or unexported and has never before been defined, the variable will not be exported.
|
|
|
|
In query mode, the scope to be examined can be specified.
|
|
Whether the variable has to be a path variable or exported can also be specified.
|
|
|
|
In erase mode, if variable indices are specified, only the specified slices of the list variable will be erased.
|
|
|
|
``set`` requires all options to come before any other arguments.
|
|
For example, ``set flags -l`` will have the effect of setting the value of the variable :envvar:`flags` to '-l', not making the variable local.
|
|
|
|
Exit status
|
|
-----------
|
|
|
|
In assignment mode, ``set`` does not modify the exit status, but passes along whatever :envvar:`status` was set, including by command substitutions.
|
|
This allows capturing the output and exit status of a subcommand, like in ``if set output (command)``.
|
|
|
|
In query mode, the exit status is the number of variables that were not found.
|
|
|
|
In erase mode, ``set`` exits with a zero exit status in case of success, with a non-zero exit status if the commandline was invalid, if any of the variables did not exist or was a :ref:`special read-only variable <variables-special>`.
|
|
|
|
|
|
Examples
|
|
--------
|
|
|
|
Print all global, exported variables::
|
|
|
|
> set -gx
|
|
|
|
Set the value of the variable _$foo_ to be 'hi'.::
|
|
|
|
> set foo hi
|
|
|
|
Append the value "there" to the variable $foo::
|
|
|
|
> set -a foo there
|
|
|
|
Remove _$smurf_ from the scope::
|
|
|
|
> set -e smurf
|
|
|
|
Remove _$smurf_ from the global and universal scopes::
|
|
|
|
> set -e -Ug smurf
|
|
|
|
Change the fourth element of the $PATH list to ~/bin::
|
|
|
|
> set PATH[4] ~/bin
|
|
|
|
Outputs the path to Python if ``type -p`` returns true::
|
|
|
|
if set python_path (type -p python)
|
|
echo "Python is at $python_path"
|
|
end
|
|
|
|
Setting a variable doesn't modify $status; a command substitution still will, though::
|
|
|
|
> echo $status
|
|
0
|
|
> false
|
|
> set foo bar
|
|
> echo $status
|
|
1
|
|
> true
|
|
> set foo banana (false)
|
|
> echo $status
|
|
1
|
|
|
|
``VAR=VALUE command`` sets a variable for just one command, like other shells.
|
|
This runs fish with a temporary home directory::
|
|
|
|
> HOME=(mktemp -d) fish
|
|
|
|
(which is essentially the same as)::
|
|
|
|
> begin; set -lx HOME (mktemp -d); fish; end
|
|
|
|
Notes
|
|
-----
|
|
- Fish versions prior to 3.0 supported the syntax ``set PATH[1] PATH[4] /bin /sbin``, which worked like ``set PATH[1 4] /bin /sbin``.
|