shell 调试

shell脚本的调试

Shell本身提供一些调试方法选项：

-n，读一遍脚本中的命令但不执行，用于检查脚本中的语法错误。
-v，一边执行脚本，一边将执行过的脚本命令打印到标准输出。
-x，提供跟踪执行信息，将执行的每一条命令和结果依次打印出来。
使用这些选项有三种方法(注意:避免几种调试选项混用)

1.在命令行提供参数：$sh -x script.sh
2.脚本开头提供参数：#!/bin/sh -x
3.在脚本中用set命令启用or禁用参数：其中set -x表示启用，set +x表示禁用。

1. 运行脚本时，添加-x选项

$ bash -x script-name
$ bash -x domains.sh
$ sh -x script_name

2. 在脚本中开启编译选项

#!/bin/bash
clear
 
# turn on debug mode
set -x
for f in *
do
   file $f
done
# turn OFF debug mode
set +x
ls
# more commands

说明：

set -x Prints the statements after interpreting metacharacters and variables
set +x Stops the printing of statements
set -v Prints the statements before interpreting metacharacters and variables
set -f Disables file name generation (using metacharacters)

3. 解释器参数

#!/bin/bash -xv
#!/bin/sh -x

4.使用Debug变量和函数来实现

#!/bin/bash
_DEBUG="on"
function DEBUG()
{
 [ "$_DEBUG" == "on" ] &&  $@
}
 
DEBUG echo 'Reading files'
for i in *
do
  grep 'something' $i > /dev/null
  [ $? -eq 0 ] && echo "Found in $i file"
done
DEBUG set -x
a=2
b=3
c=$(( $a + $b ))
DEBUG set +x
echo "$a + $b = $c"

5. 使用日志打印

（1.）下载log4shell.sh脚本

https://github.com/fredpalmer/log4bash/blob/master/log4bash.sh

（2.）日志打印

#!/usr/bin/env bash
source log4bash.sh

log "This is regular log message... log and log_info do the same thing";

log_warning "Luke ... you turned off your targeting computer";
log_info "I have you now!";
log_success "You're all clear kid, now let's blow this thing and go home.";
log_error "One thing's for sure, we're all gonna be a lot thinner.";

# If you have figlet installed -- you'll see some big letters on the screen!
log_captains "What was in the captain's toilet?";

# If you have the "say" command (e.g. on a Mac)
log_speak "Resistance is futile";

相关链接

https://www.cyberciti.biz/tips/debugging-shell-script.html
https://www.cnblogs.com/anliven/p/6032081.html

https://www.thegeekdiary.com/how-to-debug-shell-scripts/