Bash 中的错误处理 [英] Error handling in Bash

问题描述

你最喜欢用什么方法来处理 Bash 中的错误?我在网络上发现的处理错误的最佳示例是 William Shotts, Jr 在 http://www.linuxcommand.org 上编写的.

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.

他建议在 Bash 中使用以下函数进行错误处理:

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."

您在 Bash 脚本中是否有更好的错误处理例程?

Do you have a better error handling routine that you use in Bash scripts?

推荐答案

使用陷阱！

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

...然后，每当您创建临时文件时:

...then, whenever you create a temporary file:

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

和 $temp_foo 将在退出时被删除，并打印当前行号.(set -e 同样会给你退出错误行为，虽然它来了有严重的警告并削弱代码的可预测性和可移植性).

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, though it comes with serious caveats and weakens code's predictability and portability).

您可以让陷阱为您调用 error(在这种情况下，它使用默认退出代码 1 并且没有消息)或自己调用它并提供显式值；例如:

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

将以状态 2 退出，并给出明确的消息.

will exit with status 2, and give an explicit message.

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