在Bash中处理错误

问题描述

你最喜欢的方法是什么来处理Bash中的错误？
在网页上找到的错误处理最好的例子是William Shotts，Jr在。他建议在Bash中使用以下函数进行错误处理：

 ＃＃/ bin / bash 
 
＃一个slicker错误处理例程
 
＃我在我的脚本中放了一个名为PROGNAME的变量，
＃程序正在运行。您可以从命令行（$ 0）的第一个项目获取
＃的值。 
 
＃参考：这是从< http：//www.linuxcommand.org/wss0150.php> 
 
 PROGNAME = $（basename $ 0）
 
函数error_exit 
 {
 
＃----------- -------------------------------------------------- --- 
＃由于致命程序错误而退出的功能
＃接受1个参数：
包含描述性错误消息的字符串
＃---------- -------------------------------------------------- ---- 
 
 echo$ {PROGNAME}：$ {1： - 未知错误}1& 2 
退出1 
} 
 
＃示例调用error_exit函数。注意包含
＃的LINENO环境变量。它包含当前的
＃行号。 
 
 echo行号和消息
 error_exit的错误示例$ LINENO：发生错误。 
  

您是否在Bash脚本中使用了更好的错误处理例程？

解决方案

使用陷阱

  tempfiles = ）
 cleanup（）{
 rm -f$ {tempfiles [@]}
} 
陷阱清理0 
 
错误（）{
本地parent_lineno =$ 1
本地消息=$ 2
本地代码=$ {3：-1}
如果[[-n$ message]] ;然后
 echo错误在$ {parent_lineno}上或附近：$ {message};退出状态$ {code}
 else 
 echo错误在或附近$ {parent_lineno} ;退出状态$ {code}
 fi 
退出$ {code}
} 
陷阱'错误$ {LINENO}'ERR 
  

...然后，每当您创建一个临时文件：

  temp_foo =$（mktemp -t foobar.XXXXXX）
 tempfiles + =（$ temp_foo）
  

和 $ temp_foo 将在退出时删除，并打印当前行号。 （ set -e 同样会给你错误的退出行为，并削弱了代码的可预测性和可移植性。）

您可以让陷阱调用错误（在这种情况下，它使用默认退出代码1，没有消息）或自己调用并提供显式值;例如：

 错误$ {LINENO}foobar failed2 
  / pre> 
 
 
将退出状态2，并给出明确的消息。
 
What is your favorite method to handle errors in Bash?
The best example of handling errors I have found on the web was written by William Shotts, Jr at http://www.linuxcommand.org. 

He suggests using the following function for error handling in Bash:
#!/bin/bash

# A slicker error handling routine

# I put a variable in my scripts named PROGNAME which
# holds the name of the program being run.  You can get this
# value from the first item on the command line ($0).

# Reference: This was copied from <http://www.linuxcommand.org/wss0150.php>

PROGNAME=$(basename $0)

function error_exit
{

#   ----------------------------------------------------------------
#   Function for exit due to fatal program error
#       Accepts 1 argument:
#           string containing descriptive error message
#   ----------------------------------------------------------------

    echo "${PROGNAME}: ${1:-"Unknown Error"}" 1>&2
    exit 1
}

# Example call of the error_exit function.  Note the inclusion
# of the LINENO environment variable.  It contains the current
# line number.

echo "Example of error with line number and message"
error_exit "$LINENO: An error has occurred."
Do you have a better error handling routine that you use in Bash scripts?
 解决方案 
Use a trap!
tempfiles=( )
cleanup() {
  rm -f "${tempfiles[@]}"
}
trap cleanup 0

error() {
  local parent_lineno="$1"
  local message="$2"
  local code="${3:-1}"
  if [[ -n "$message" ]] ; then
    echo "Error on or near line ${parent_lineno}: ${message}; exiting with status ${code}"
  else
    echo "Error on or near line ${parent_lineno}; exiting with status ${code}"
  fi
  exit "${code}"
}
trap 'error ${LINENO}' ERR
...then, whenever you create a temporary file:
temp_foo="$(mktemp -t foobar.XXXXXX)"
tempfiles+=( "$temp_foo" )
and $temp_foo will be deleted on exit, and the current line number will be printed. (set -e will likewise give you exit-on-error behavior,  and weakens code's predictability and portability).
You can either let the trap call error for you (in which case it uses the default exit code of 1 and no message) or call it yourself and provide explicit values; for instance:
error ${LINENO} "the foobar failed" 2
will exit with status 2, and give an explicit message.
                        
这篇关于在Bash中处理错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！