Is there a TRY CATCH command in Bash? No. Bash doesn't have as many luxuries as one can find in many programming languages. There is no try/catch in bash; however, one can achieve similar behavior using && or ||. Using ||: if command1 fails then c…

最近在使用chroot去重新的挂载一个根目录,总是出现上面的问题,很烦,好久了没有解决, 然后自己就写了一个复制依赖库的脚本,然后发现可以切换了,然后就重新试着去挂载根目录 终于发现了原因. ------------------------------------------------------------------------------------------------ chroot /mnt/sysroot 为使用/mnt/sysroot为新根挂载的命令,一般只是需要创建完目录之后…

1 使用chroot命令时报错如下: testupgrade:/ # chroot /sb chroot: cannot change root directory to /sb: No such file or directory 2 通过下面命令可以看到,当前连接的shell环境是bash,所有系统默认会在chroot的时候切换shell testupgrade:/ # echo $SHELL /bin/bash 3 解决办法:当然是把bash拷贝到chroot的路径下了 3.1 首先要把b…

How do I use bash for loop to repeat certain task under Linux / UNIX operating system? How do I set infinite loops using for statement? How do I use three-parameter for loop control expression? A 'for loop' is a bash programming language statement wh…

1. 区别 builtin command, external command,bash script. 用builtin command(hash.type.command),而不是which命令(external command)查看某个命令是安装了(跟PATH变量相关): hash foo >/dev/null 2>&  1 || echo "I need the command but it not exist" 或者 command -v foo >…

Hyperpolyglot Unix Shells: Bash, Fish, Ksh, Tcsh, Zsh grammar | quoting and escaping | charactersvariables | variable expansion | brace, tilde, command, and pathname expansion | special variablesarithmetic and conditional expressionsarrays | associat…

Sequence 1: Configuring the bash Shell Deliverable: A system with new aliases that clear the screen, and produce a useful timesortedls listing. Instructions: 1. You have decided to create an alias so that when you type c, the system will run the clea…

原文链接,转载请注明出处: http://www.happycxz.com/m/?p=137 常见shell类型 Bourne shell (sh) UNIX 最初使用,且在每种 UNIX 上都可以使用. 在 shell 编程方面相当优秀,但在处理与用户的交互方面做得不如其他几种shell. C shell (csh) csh, the C shell, is a command interpreter with a syntax similar to the C programming lan…

什么是shell? bash和shell有什么关系? 博客分类: Linux   什么是Shell?      shell是你(用户)和Linux(或者更准确的说,是你和Linux内核)之间的接口程序.你在提示符下输入的每个命令都由shell先解释然后传给Linux内核.      shell 是一个命令语言解释器(command-language interpreter).拥有自己内建的 shell 命令集.此外,shell也能被系统中其他有效的Linux 实用程序和应用程序(utilitie…

cat docker-compose.yml version: '3.4' services: klvchen: image: python_django:19.03.0 ports: - 8000:8000 command: - /bin/bash - -c - | cd /app01 python manage.py runserver 0.0.0.0:8000 volumes: - /iba/app01:/app01…