This will test whether the variable$foois equal to the string*ar. It will work even if$foois empty because the quotation marks will force an empty string comparison. The quotes around*arwill prevent the shell from interpolating the glob. This is a true equality. 这将测试变量$ foo是否等于...
Example 2: Check if strings are not equal in Bash Instead of checking the quality, let’s do the opposite and check the inequality. Bash also provides the negation operator so that you can easily use “if not equal” condition in shell scripts. if [ "$string1" != "Not MyString" ] ...
'Else if'in bash scripting, often written as'elif', is used to check multiple conditions in your code. It is used with the syntax,if [firstStatement]; then... elif [secondCondition]; then... else. It’s a powerful tool that allows your scripts to make decisions based on various scen...
/bin/BashS1="Hello World"S2="Hello World"if["$S1"="$S2"]thenecho"Equal"elseecho"Not Equal"fi The following script contains two strings, S1 and S2, that have the same value. The if condition uses the = operator to compare the strings; however, we can also useif [ "$S1" == "$...
string.sh #! /bin/bash word=a if [[ $word == "b" ]] then echo "condition b is true" elif [[ $word == "a" ]] then echo "condition a is true" else echo "condition is false" fi bash Shell Useful tools for Programmers ...
# Code block executed when condition is false fi Conditions of using if statement Bash provides several conditionals that you can use within if statements: 1. Numeric Comparisons: -eq: Equal to -ne: Not equal to -gt: Greater than -lt: Less than ...
Example 1: If statement in bash on string equality #!/bin/bash read-p"Enter a match word: "USER_INPUT if[[$USER_INPUT=="hello"]];then echo"Hello to you as well" fi In this example above we use the basicIFcondition with a single test of string equality and then print some output...
1 if [ condition1 ] 2 then 3 command1 4 command2 5 command3 6 elif [ condition2 ] 7 # Same as else if 8 then 9 command4 10 command5 11 else 12 default-command 13 fi使用if test condition-true这种形式和if[condition-true]这种形式是等价的.向我们前边所说的"["是test的标记.并且以"...
1) if/then结构: 判断命令列表的退出码是否为0,0为成功。 如果if和then在条件判断的同一行上的话, 必须使用分号来结束if表达式; if和then都是关键字。 关键字(或者命令)如果作为表达式的开头, 并且如果想在同一行上再写一个新的表达式的话, 那么必须使用分号来结束上一句表达式。 if [ condition1 ] then co...
"*." from the beginning of the string contained in the environment variable "1", returning the result. This will cause everything after the last "." in the file to be returned. Obviously, if the file ends in ".tar", we will get "tar" as a result, and the condition will be true...