the first action is performed; otherwise, the action following the else segment is performed. If there are more than two sets of instructions, one or more elif statements may be used to specify alternative sequences of action.
“Sometimes, it requires executing one or more statements based on a particular condition. This problem can be solved by using the “if” statement. It is a very useful statement for any programming language. The ways of using different types of “if” statements in the PERL script have ...
Shell中判断语句if中-z至-d的意思 - sunny_2015 - 博客园 https://www.cnblogs.com/coffy/p/5748292.html Conditions in bash scripting (if statements) - Linux Academy Blog https://linuxacademy.com/blog/linux/conditions-in-bash-scripting-if-statements/ Table of conditions The following table list ...
Python 中的循环语句有 for 和 while。...1.while 语句Python 中 while 语句的一般形式:while 判断条件condition: 执行语句statements同样需要注意冒号和缩进。...while 后面的条件语句为 false 时,则执行 else 的语句块。...,可以将该语句与while写在同一行中。...continue 语句跳过当前循环块中的剩余语句,然后...
Nginx if else, Using if/else Statements in Nginx Configuration, Using Arguments to Incorporate If-Else Statements in Nginx Configuration File, Else statement missing in Nginx location block with if condition
Related:How to Check If a File Exists in Linux Bash Scripts A Simple If Statement Example This is the canonical form of the simplestifstatement: if [ this-condition-is-true ] then execute-these-statements fi If the condition within the text resolves to true, the lines of script in thethe...
这只是通常的情况,例如diff,0表示你no difference,1表示difference,2表示错误。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$?来查看上一命令执行的结果。例如我们希望用一个新的cd命令来替代原来在linux ...
这只是通常的情况,例如diff,0表示你no difference,1表示difference,2表示错误。if判断statements的最后一个的exit status,通常我们只放一个statement,如果为0,表示true,否则表示false。 执行下一条命令会冲掉原来exit status。可以使用$?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 ...
case expression in pattern1) statements ;; pattern2) statements ...
case expression in pattern1 ) statements ;; pattern2 ) statements ;; ... esac Example: #! /bin/bash ARCH=$(uname -m) case $ARCH in armv6*) ARCH="armv6";; armv7*) ARCH="arm";; aarch64) ARCH="arm64";; x86) ARCH="386";; x86_64) ARCH="amd64";; i686) ARCH="386";;...