Shell 调试

没错, shell也可以调试.

看这样一个脚本:

$ cat filesize.sh
#!/bin/bash
for filesize in $(ls -l . | grep "^-" | awk '{print $5}')
do
let totalsize=$totalsize+$filesize
done
echo "Total file size in current directory: $totalsize"

运行结果如下:

$ ./filesize.sh
Total file size in current directory: 652

添加调试信息:

$ cat filesize.sh
#!/bin/bash
set -xv   ## 注意这里!
for filesize in $(ls -l . | grep "^-" | awk '{print $5}')
do
let totalsize=$totalsize+$filesize
done
echo "Total file size in current directory: $totalsize"

输出结果如下:

$ ./fs.sh
++ ls -l .
++ grep '^-'
++ awk '{print $5}'
+ for filesize in '$(ls -l . | grep "^-" | awk '\''{print
$5}'\'')'
+ let totalsize=+178
+ for filesize in '$(ls -l . | grep "^-" | awk '\''{print
$5}'\'')'
+ let totalsize=178+285
+ for filesize in '$(ls -l . | grep "^-" | awk '\''{print
$5}'\'')'
+ let totalsize=463+189
+ echo 'Total file size in current directory: 652'
Total file size in current directory: 652

每次执行一条命令都会输出对应的命令和结果.

除了上面的方法, 还可以这样调试:

$ bash -xv filesize.sh

直接在运行的时候调试.

很有用的我会乱说~