fish-shell/share/functions/alias.fish
Johannes Altmanninger f20e8e5860 alias: don't add --wraps for wrappers with the same name
These aliases seem to be common, see #7389 and others.  This prevents
recursion on that example, so `alias ssh "env TERM=screen ssh"` will just
have the same completions as ssh.

Checking the last token is a heuristic which hopefully works for most
cases. Users are encouraged to use functions instead of aliases.
2020-10-10 09:24:49 +02:00

74 lines
2.3 KiB
Fish

function alias --description 'Creates a function wrapping a command'
set -l options h/help s/save
argparse -n alias --max-args=2 $options -- $argv
or return
if set -q _flag_help
__fish_print_help alias
return 0
end
set -l name
set -l body
set -l prefix
if not set -q argv[1]
# Print the known aliases.
for func in (functions -n)
set -l output (functions $func | string match -r -- "^function .* --description (?:'alias (.*)'|alias\\\\ (.*))\$")
if set -q output[2]
set output (string replace -r -- '^'$func'[= ]' '' $output[2])
echo alias $func (string escape -- $output[1])
end
end
return 0
else if not set -q argv[2]
# Alias definition of the form "name=value".
set -l tmp (string split -m 1 "=" -- $argv) ""
set name $tmp[1]
set body $tmp[2]
else
# Alias definition of the form "name value".
set name $argv[1]
set body $argv[2]
end
# sanity check
if test -z "$name"
printf ( _ "%s: Name cannot be empty\n") alias
return 1
else if test -z "$body"
printf ( _ "%s: Body cannot be empty\n") alias
return 1
end
# Extract the first command from the body.
printf '%s\n' $body | read -l --list words
set -l first_word $words[1]
set -l last_word $words[-1]
# Prevent the alias from immediately running into an infinite recursion if
# $body starts with the same command as $name.
if test $first_word = $name
if contains $name (builtin --names)
set prefix builtin
else
set prefix command
end
end
set -l cmd_string (string escape -- "alias $argv")
# Do not define wrapper completion if we have "alias foo 'foo xyz'" or "alias foo 'sudo foo'"
# This is to prevent completions from recursively calling themselves (#7389).
# The latter will have rare false positives but it's more important to
# prevent recursion for this high-level command.
set -l wraps
if test $first_word != $name; and test $last_word != $name
set wraps --wraps (string escape -- $body)
end
echo "function $name $wraps --description $cmd_string; $prefix $body \$argv; end" | source
if set -q _flag_save
funcsave $name
end
end