fish-shell/share/functions/umask.fish
Kurtis Rader 62244f01c2 fix umask handling of symbolic modes
This fixes the handling of symbolic umask values. It also removes two
invocations of `perl` and all but two `math` commands.

Fixes #738
2017-03-28 16:28:24 -07:00

222 lines
6.3 KiB
Fish

# Support the usual (i.e., bash compatible) `umask` UI. This reports or modifies the magic global
# `umask` variable which is monitored by the fish process.
# This table is indexed by the base umask value to be modified. Each digit represents the new umask
# value when the permissions to add are applied to the base umask value.
set __fish_umask_add_table 0101010 2002200 2103210 4440000 4541010 6442200 6543210
function __fish_umask_add
set -l mask_digit $argv[1]
set -l to_add $argv[2]
set -l mask_table 0000000
if test $mask_digit -gt 0
set mask_table $__fish_umask_add_table[$mask_digit]
end
set -l new_vals (string split '' $mask_table)
echo $new_vals[$to_add]
end
# This table is indexed by the base umask value to be modified. Each digit represents the new umask
# value when the permissions to remove are applied to the base umask value.
set __fish_umask_remove_table 1335577 3236767 3337777 5674567 5775577 7676767 7777777
function __fish_umask_remove
set -l mask_digit $argv[1]
set -l to_remove $argv[2]
set -l mask_table 1234567
if test $mask_digit -gt 0
set mask_table $__fish_umask_remove_table[$mask_digit]
end
set -l new_vals (string split '' $mask_table)
echo $new_vals[$to_remove]
end
# This returns the mask corresponding to allowing the permissions to allow. In other words it
# returns the inverse of the mask passed in.
set __fish_umask_set_table 6 5 4 3 2 1 0
function __fish_umask_set
set -l to_set $argv[1]
if test $to_set -eq 0
return 7
end
echo $__fish_umask_set_table[$to_set]
end
# Given a umask string, possibly in symbolic mode, return an octal value with leading zeros.
# This function expects to be called with a single value.
function __fish_umask_parse
# Test if already a valid octal mask. If so pad it with zeros and return it.
# Note that umask values are always base 8 so they don't require a leading zero.
if string match -qr '^0?[0-7]{1,3}$' -- $argv
string sub -s -4 0000$argv
return 0
end
# Test if argument is a valid symbolic mask. Note that the basic pattern allows one illegal
# pattern: who and perms without a mode such as "urw". We test for that below after using the
# pattern to split the rights then testing for that invalid combination.
set -l basic_pattern '([ugoa]*)([=+-]?)([rwx]*)'
if not string match -qr "^$basic_pattern(,$basic_pattern)*\$" -- $argv
printf (_ "%s: Invalid mask '%s'\n") umask $argv >&2
return 1
end
# Split umask into individual digits. We erase the first one because it should always be zero.
set -l res (string split '' $umask)
set -e res[1]
for rights in (string split , $argv)
set -l match (string match -r "^$basic_pattern\$" $rights)
set -l scope $match[2]
set -l mode $match[3]
set -l perms $match[4]
if test -n "$scope" -a -z "$mode"
printf (_ "%s: Invalid mask '%s'\n") umask $argv >&2
return 1
end
if test -z "$scope"
set scope a
end
if test -z "$mode"
set mode =
end
set -l scopes_to_modify
string match -q '*u*' $scope
and set scopes_to_modify 1
string match -q '*g*' $scope
and set scopes_to_modify $scopes_to_modify 2
string match -q '*o*' $scope
and set scopes_to_modify $scopes_to_modify 3
string match -q '*a*' $scope
and set scopes_to_modify 1 2 3
set -l val 0
if string match -q '*r*' $perms
set val 4
end
if string match -q '*w*' $perms
set val (math $val + 2)
end
if string match -q '*x*' $perms
set val (math $val + 1)
end
for j in $scopes_to_modify
switch $mode
case '='
set res[$j] (__fish_umask_set $val)
case '+'
set res[$j] (__fish_umask_add $res[$j] $val)
case '-'
set res[$j] (__fish_umask_remove $res[$j] $val)
end
end
end
echo 0$res[1]$res[2]$res[3]
return 0
end
function __fish_umask_print_symbolic
set -l val
set -l res ""
set -l letter a u g o
for i in 2 3 4
set res $res,$letter[$i]=
set val (echo $umask|cut -c $i)
if contains $val 0 1 2 3
set res {$res}r
end
if contains $val 0 1 4 5
set res {$res}w
end
if contains $val 0 2 4 6
set res {$res}x
end
end
echo (string split -m 1 '' -- $res)[2]
end
function umask --description "Set default file permission mask"
set -l as_command 0
set -l symbolic 0
set -l options
set -l shortopt pSh
if not getopt -T >/dev/null
# GNU getopt
set longopt -l as-command,symbolic,help
set options -o $shortopt $longopt --
# Verify options
if not getopt -n umask $options $argv >/dev/null
return 1
end
else
# Old getopt, used on OS X
set options $shortopt
# Verify options
if not getopt $options $argv >/dev/null
return 1
end
end
set -l tmp (getopt $options $argv)
eval set opt $tmp
while count $opt >/dev/null
switch $opt[1]
case -h --help
__fish_print_help umask
return 0
case -p --as-command
set as_command 1
case -S --symbolic
set symbolic 1
case --
set -e opt[1]
break
end
set -e opt[1]
end
switch (count $opt)
case 0
if not set -q umask
set -g umask 113
end
if test $as_command -eq 1
echo umask $umask
else
if test $symbolic -eq 1
__fish_umask_print_symbolic $umask
else
echo $umask
end
end
case 1
if set -l parsed (__fish_umask_parse $opt)
set -g umask $parsed
return 0
end
return 1
case '*'
printf (_ '%s: Too many arguments\n') umask >&2
return 1
end
end