The exit status of the wait command is printed. $? is an internal Bash variable that holds the exit status of the last command executed. If you run the script, it will print something like this: PID: 36353 Exit status: 0 Here’s an example using the -n option: #!/bin/bash sleep ...
In Bash you can start new processes (theads) on the background simply by running a command with ampersand &. The wait command can be used to wait until all background processes have finished (to wait for a certain process do wait PID where PID is a process ID). So here’s a simple...
4.bash的执行过程1>命令的执行是从上到下,从左到右的分析与执行2>命令执行时,命令和参数间的多个空白都会被忽略3>空白行也会被忽略4>没读取一个Enter字符,就开始执行该程序5>“#”作为批注,任何加在#后面的数据都将视为批注6>shell script 都是以*.sh结尾,而且一个shell脚本能否被执行,必须得有x权限7>ba...
用法1: 假设你的入口脚本是 myscript.sh,可以新建一个脚本,通过 flock 来运行它: # flock --wait 超时时间 -e 锁文件 -c "要执行的命令" # 例如: flock --wait 5 -e "lock_myscript" -c "bash myscript.sh" 用法2: 也可以在原有脚本里使用 flock。 可以把文件打开为一个文件描述符,然后使用 ...
Linux Shell简介 Shell脚本通常是一个以shebang(#!/bin/bash)起始的文本文件,其中/bin/bash是Bash的解释器命令路径。 Shell脚本有两种运行方式: 一种是将脚本作为bash的命令行参数,如: $bashscript.sh #假设脚本位于当前目录下 $bash/home/path/script.sh #使用脚本的完整路径 另一种则是授予脚本执行权 ...
of using the WAIT command to control how bash executes your commands. The bash WAIT command is used to halt the execution of a script until all background jobs or specified JobID/PIDs terminate successfully and return an expected exit code to trigger the next command that was “waited for....
command &>filename 重定向command的标准输出(stdout)和标准错误(stderr)到文件filename中; command >&2 把command的标准输出(stdout)重定向到标准错误(stderr)中; scriptname >>filename 把scriptname的输出(同>)追加到文件filenmae中,如果文件不存在则创建。
alias name = 'command' alias name = 'command arg1 arg2' alias name = '/path/to/script' alias name = '/path/to/script.pl arg1' 举个例子,输入下面命令并回车就会为常用的clear(清除屏幕)命令创建一个别名c: alias c = 'clear' 然后输入字母c而不是clear后回车就会清除屏幕了: ...
Install & Update ScriptTo install or update nvm, you should run the install script. To do that, you may either download and run the script manually, or use the following cURL or Wget command:curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.3/install.sh | bash...
_STRPERROR_() { # run on script error local RV="$?" printf "\\e[?25h\\n\\e[1;48;5;138m %s\\e[0m\\n" "TermuxArch WARNING: Generated script signal ${RV:-unknown} near or at line number ${1:-unknown} by \`${2:-command}\`!" if [[ "$RV" = 4 ]] then ...