对于多个命令，是否有类似于pipefail的东西，比如'try'语句，但在bash中。我想这样做:
echo "trying stuff"
try {
command1
command2
command3
}
在任何时候，如果任何命令失败了，就退出并回显该命令的错误。我不想做这样的事情:
command1
if [ $? -ne 0 ]; then
echo "command1 borked it"
fi
command2
if [ $? -ne 0 ]; then
echo "command2 borked it"
fi
等等……或者类似的事情:
pipefail -o
command1 "arg1" "arg2" | command2 "arg1" "arg2" | command3
因为我相信每个命令的参数(如果我错了请纠正我)会相互干扰。这两种方法对我来说似乎非常冗长和讨厌，所以我在这里呼吁一种更有效的方法。
当前回答
你说的“退出并回复错误”是什么意思?如果您的意思是希望脚本在任何命令失败时立即终止，那么就这样做
set -e # DON'T do this. See commentary below.
在脚本的开头(但注意下面的警告)。不要回显错误消息:让失败的命令处理它。换句话说，如果你这样做:
#!/bin/sh
set -e # Use caution. eg, don't do this
command1
command2
command3
而command2失败，同时打印一个错误消息到stderr，那么似乎您已经实现了您想要的。(除非我误解了你想要的!)
因此，您编写的任何命令都必须表现良好:它必须向stderr而不是stdout报告错误(问题中的示例代码将错误输出到stdout)，并且在失败时必须以非零状态退出。
However, I no longer consider this to be a good practice. set -e has changed its semantics with different versions of bash, and although it works fine for a simple script, there are so many edge cases that it is essentially unusable. (Consider things like: set -e; foo() { false; echo should not print; } ; foo && echo ok The semantics here are somewhat reasonable, but if you refactor code into a function that relied on the option setting to terminate early, you can easily get bitten.) IMO it is better to write:
#!/bin/sh
command1 || exit
command2 || exit
command3 || exit
or
#!/bin/sh
command1 && command2 && command3
其他回答
run() {
$*
if [ $? -ne 0 ]
then
echo "$* failed with exit code $?"
return 1
else
return 0
fi
}
run command1 && run command2 && run command3
就我个人而言，我更喜欢使用轻量级方法，如下所示;
yell() { echo "$0: $*" >&2; }
die() { yell "$*"; exit 111; }
try() { "$@" || die "cannot $*"; }
asuser() { sudo su - "$1" -c "${*:2}"; }
使用示例:
try apt-fast upgrade -y
try asuser vagrant "echo 'uname -a' >> ~/.profile"
以功能的方式检查状态
assert_exit_status() {
lambda() {
local val_fd=$(echo $@ | tr -d ' ' | cut -d':' -f2)
local arg=$1
shift
shift
local cmd=$(echo $@ | xargs -E ':')
local val=$(cat $val_fd)
eval $arg=$val
eval $cmd
}
local lambda=$1
shift
eval $@
local ret=$?
$lambda : <(echo $ret)
}
用法:
assert_exit_status 'lambda status -> [[ $status -ne 0 ]] && echo Status is $status.' lls
输出
Status is 127
不要创建runner函数或使用set -e，而是使用trap:
trap 'echo "error"; do_cleanup failed; exit' ERR
trap 'echo "received signal to stop"; do_cleanup interrupted; exit' SIGQUIT SIGTERM SIGINT
do_cleanup () { rm tempfile; echo "$1 $(date)" >> script_log; }
command1
command2
command3
该trap甚至可以访问触发它的命令的行号和命令行。变量为$BASH_LINENO和$BASH_COMMAND。
对不起，我不能对第一个答案发表评论 但是你应该使用新实例来执行命令:
#!/bin/bash
function check_exit {
cmd_output=$($@)
local status=$?
echo $status
if [ $status -ne 0 ]; then
echo "error with $1" >&2
fi
return $status
}
function run_command() {
exit 1
}
check_exit run_command
