if-else statements in Linux may not execute due to logical errors in the script. These errors may arise from incorrect logic in the if-else statements, such as using the wrong variables, referencing undefined variables, or making incorrect assumptions about the flow of the script. To troublesho...
Illustrated below is an example that demonstrates the use of if-else statements in the server directive to define conditions. The if-else code is being placed within the server directive, but it can also be written into location directive . Since the else statement is not supported in nginx, ...
statements ;; esac 让我们看一个输入和判断操作系统的例子,脚本如下: #!/bin/bash echo "Which is Your Favorite Linux Distro?" echo "Debian, Ubuntu, SUSE, RHEL, Arch" read -p "Type Your Linux Distro:" OS case $OS in Debian) echo "Most Stable Linux OS, good choice " ;; Ubuntu) echo...
if判断statements的最后一个的exit status,通常我们只放一个statement,如果为0,表示true,否则表示false。 执行下一条命令会冲掉原来exit status。可以使用$?来查看上一命令执行的结果。例如我们希望用一个新的cd命令来替代原来在linux kernel中已将编译的cd命令,由于function是优先于built-in命令,所以调用时,将调用我...
1、if语法格式 1.1 if格式 if condition; then commands; fi 1.2 else if 和 else if c...
if判断statements的最后一个的exit status,通常我们只放一个statement,如果为0,表示true,否则表示false。执行下一条命令会冲掉原来exit status。可以使用$?来查看上一命令执行的结果。例如我们希望用一个新的cd命令来替代原来在linux kernel中已将编译的cd命令,由于function是优先于built-in命令,所以调用时,将调用我们...
statements ;; *) statements ;; esac 让我们看一个输入和判断操作系统的例子,脚本如下: #!/bin/bash echo "Which is Your Favorite Linux Distro?" echo "Debian, Ubuntu, SUSE, RHEL, Arch" read -p "Type Your Linux Distro:" OS case $OS in ...
statements ;; esac 让我们看一个输入和判断操作系统的例子,脚本如下: #!/bin/bash echo "Which is Your Favorite Linux Distro?" echo "Debian, Ubuntu, SUSE, RHEL, Arch" read -p "Type Your Linux Distro:" OS case $OS in Debian) echo "Most Stable Linux OS, good choice " ...
[elsestatements ] fi 示例 vi if.sh #!/bin/bashif[ $1 =root ] then echo"hello $2 , welcome !"elif[ $1 =intsmaze ] then echo"hello ${2}, welcome !"elseecho"SB${2}, get out here !"fi sh if.sh intsmaze nihao 通过执行脚本时,在脚本命令的后面传入参数。
for expression1 in iterable: for_suite else: else_suite Note:通常,expression或是一个单独的变量,或是一个变量序列,一般以元组的形式给出 如果以元组或列表用于expression,则其中的每个数据都会拆分表达式的项 D、编写循环的技巧 a. for循环比while循环执行速度快 ...