If a command executes successfully in bash, it has a 0 exit code. For command not found, the exit code is 127. Therefore, we can use the exit code to perform a specific action. This tutorial will give you a few
如果你想要在标准输出同时输出自定义的错误提示,可以使用复合命令(command grouping[17]): cd /net || { echo "Can't read /net. Make sure you've logged in to the Samba network, and try again."; exit 1; } do_stuff more_stuff 注意,在{号和 echo 之间需要有一个空格,同时}之前要加上分号。
EN连续两次求贤令：曾经我给你带来了十万用户，但现在祝你倒闭，以及 生信技能树知识整理实习生招募，让...
ifgrep-q fooregex myfile;then...fi 如果grep 在 myfile 中找到匹配的行,它的执行结果为 0(true),then 后面的部分就会执行。 10. if [bar="$foo"]; then ... 正如上一个问题中提到的,[是一个命令,它的参数之间必须用空格分隔。 11. if [ [ a = b ] && [ c = d ] ]; then ... 不...
cd/foo ||exit1bar baz bat ...# Lots of commands. 1. 2. 3. 4. 出错时,cd 命令会报告无法改变当前目录,同时将错误消息输出到标准错误,例如 "bash: cd: /foo: No such file or directory"。如果你想要在标准输出同时输出自定义的错误提示,可以使用复合命令(command grouping[17]): ...
exit is a builtin command and cause the shell to exit with a given exit status. n is the exit status of n. If n is omitted,the exit status is that of the last command executed. A function can be called on a EXIT before the shell terminates.
27. local varname=$(command) 28. export foo=~/bar 29. sed 's/$foo/good bye/' 30. tr [A-Z] [a-z] 31. ps ax | grep gedit 32. printf "$foo" 33. for i in {1..$n} 34. if [[ $foo = $bar ]] 35. if [[ $foo =~ 'some RE' ]] ...
When you execute a command or run a script, you receive an exit code. An exit code is a system response that reports success, an error, or another condit...
Next we define, the exit STATUS using operator $?: root@kali:~# STATUS="$?" root@kali:~# [ "$STATUS" -eq 0 ] && echo "STATUS OK" root@kali:~# [ "$STATUS" -ne 0 ] && echo "STATUS KO" STATUS KO STATUS equal to 0 means a success (failure if different to 0). In our ...
cd/foo ||exit1 bar baz bat ...# Lots of commands. 出错时,cd 命令会报告无法改变当前目录,同时将错误消息输出到标准错误,例如 "bash: cd: /foo: No such file or directory"。如果你想要在标准输出同时输出自定义的错误提示,可以使用复合命令(command grouping[17]): ...