Bash programming
Category: /knowledge /linuxTags: linux
Resource
Common usage
Parameters ————-
- script name: $0
- Nst parameter: $1, $2 etc
- parameter count: $#
Parse short/long parameters
Note: the following section works in bash. But it doesn’t exit for wrong format under ksh.
if ! options=$(getopt -o s:l:udh -l show:,level:,up,down,help -- "$@")
then
exit 1
fi
set -- $options
This is the common section without error checking above.
while [$# -gt 0]; do
case $1 in
-s|--show)
shift
prod_no=$1
;;
-l|--level)
shift
depth_level=$1
;;
-u|--up)
direction="UP"
;;
-d|--down)
direction="DOWN"
;;
-h|--help)
echo $usuage
exit 0
;;
esac
shift
done
get current base directory
BASEDIR=$(cd $(dirname $0); pwd)
. $BASEDIR/ksh_functions.sh
or
if [ -x "$0" ]; then
SCRIPTDIR=$(cd -P -- "$(dirname -- "$(command -v -- "$0")")" && pwd -P)
else
SCRIPT=$0
echo "${SCRIPT}" | grep "^/" > /dev/null 2>&1
if [ $? -ne 0 ]; then
SCRIPT=$(pwd)/${SCRIPT}
fi
SCRIPTDIR=$(dirname "${SCRIPT}")
fi
get current computer name
case `uname -n` in
sq*)
export MODE=TEST
;;
s[drt]*)
export MODE=PROD
;;
esac
如何从命令行传参数
举一个例子, 我想搜索一个文件时学用这个命令:
find -iname "*something*"
我想用alias来省击键次数, set alias ifind='find -iname "*$1*"', 但这个不好使.
解决的办法是在.bashrc里(当然也可以在别的文件里)定义一个function.
function ifind() {
find -iname "*$@*"
}
这样我只用在命令行里敲 ifind something 就成了.
Date
How to specify a date other than today
date +"%m%d%Y" -d 20130903
Basic control
if
if [condition]
something
then
somecode
fi
while
while [some_condition]
do
commands
done
for-loop
for i in `seq 1 10`;
do
echo $i
done
Condition checking
- [ -d “$HOME/.z” ] && echo “.z is a directory”
- [ -h “$HOME/.z” ] && echo “.z is a symlink”
- [ -z “$HOME/.z” ] && echo “.z does not exist”
- [ -f “$HOME/.z” ] && echo “.z is a file”
