fish-shell/share/functions/alias.fish
Fabian Homborg 115892ccd2 alias: Use read --tokenize
This did some weird unescaping to try to extract the first word.

So we're now more likely to be *correct*, and the alias benchmark is
about 20% *faster*.

Call it a win-win.
2019-12-01 18:14:26 +01:00

66 lines
2.1 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
set -l first_word
set -l wrapped_cmd
if not set -q argv[1]
# Print the known aliases.
for func in (functions -n)
set -l output (functions $func | string match -r -- "^function .* --description 'alias (.*)'")
if set -q output[2]
set output (string replace -r -- '^'$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 -lt first_word body
# 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")
set wrapped_cmd (string join ' ' -- $first_word $body | string escape)
echo "function $name --wraps $wrapped_cmd --description $cmd_string; $prefix $first_word $body \$argv; end" | source
if set -q _flag_save
funcsave $name
end
#echo "function $name --wraps $wrapped_cmd --description $cmd_string; $prefix $first_word $body \$argv; end"
end