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 >&2 return 1 else if test -z "$body" printf ( _ "%s: Body cannot be empty\n") alias >&2 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