请问一下 下面脚本中的 "${1#-}" != "$1" 的1#是什么意思？

274920831

#!/bin/sh
set -e

# first arg is `-f` or `--some-option`
# or first arg is `something.conf`
if [ "${1#-}" != "$1" ] || [ "${1%.conf}" != "$1" ]; then
        set -- redis-server "$@"
fi

# allow the container to be started with `--user`
if [ "$1" = 'redis-server' -a "$(id -u)" = '0' ]; then
        find . \! -user redis -exec chown redis '{}' +
        exec gosu redis "$0" "$@"
fi

exec "$@"

reyleon

语法：
${var#Pattern}, ${var##Pattern}
Remove from $var the shortest/longest part of $Pattern that matches the front end of $var.



${var%Pattern}, ${var%%Pattern}
Remove from $var the shortest/longest part of $Pattern that matches the back end of $var.

[root@hk tmp]# x=a-b+c-d+e-f+g
[root@hk tmp]#
[root@hk tmp]# echo ${x#*-}   #从左到右，删除最短匹配
b+c-d+e-f+g
[root@hk tmp]#
[root@hk tmp]# echo ${x##*-} #从左到右，删除最长匹配
f+g
[root@hk tmp]#
[root@hk tmp]# echo ${x%-*}  #从右到左，删除最短匹配
a-b+c-d+e
[root@hk tmp]#
[root@hk tmp]# echo ${x%%-*} #从右到左，删除最长匹配
a
[root@hk tmp]#

Shell_HAT

回复 1# 274920831


参考：Bash中的字符串处理
http://bbs.chinaunix.net/thread-746472-1-1.html

renxiao2003

又学习一招。