NAME

set - display and change shell variables

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 shell variables.

If both NAME and VALUE are provided, set assigns any values to variable NAME. Variables in fish are 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 scope or 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:

These options modify how variables operate:

Further options:

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:

The exporting rules when creating or updating a variable are identical to the scoping rules for variables:

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 flags to '-l', not making the variable local.

EXIT STATUS

In assignment mode, set does not modify the exit status, but passes along whatever 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 special read-only variable.

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

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