Example 1: If statement in bash on string equality #!/bin/bash read-p"Enter a match word: "USER_INPUT if[[$USER_INPUT=="hello"]];then echo"Hello to you as well" fi In this example above we use the basicIFcondition with a single test of string equality and then print some output...
So, in the end, if you want to test for string equality, you can use either[ ... ]or[[ ... ]], but you must quote your parameters. If you want to do glob pattern matching, you must leave off the quotes, and use[[ ... ]]. 因此,最后,如果要测试字符串相等性,可以使用[...]...
/bin/bash string1="MyString" string2="MyString" if [ "$string1" == "$string2" ] then echo "Equal Strings" else echo "Strings not equal" fi 💡 Pay Attention to the spaces There must be a space between the[and the variable name and the equality operator==. If you miss any of...
String comparison operators LikeIntegerandFiletest operators, we have a set of operators to work with strings. Below are the important set of string operators. -z=> Check if string is NULL.-n=> Check if string is not NULL.===> Check for string equality.!==> Check for string inequality...
HISTTIMEFORMAT If this variable is set and not null, its value is used as a format string for strftime(3) to print the time stamp associated with each history entry displayed by the history builtin. If this variable is set, time stamps are written to the history file so they may be ...
useful, let's take a look at the "if" statement used above. In it, we have a boolean expression. In bash, the "=" comparison operator checks for string equality. In bash, all boolean expressions are enclosed in square brackets. But what does the boolean expression actually test for?
1 # Correct string equality test with a bash if statement [me@linux ~]$ if [[ $myString1 == "$myString2" ]]; then echo "\$myString1 equals to \$myString2 with the string: $myString1"; else echo "\$myString1 and \$myString2 are different with \$myString1=$myString1 and...
When the `=~'operator is used, the string to the right of the operatoris matched as a regular expression. The&& and || operatorsdonot evaluate EXPR2ifEXPR1 is sufficient to determine the expression's value.Exit Status:0or1depending on value of EXPRESSION. ...
Lastly, the == operator is for checking string values for equality. ./whatIf.sh Equal! Not equal! Not equal! The if statement is used extensively in bash scripts, which means that you are going to see it many times in this guide. Loops The bash shell has support for loops, which ...
See the description of the test builtin command (section SHELL BUILTIN COMMANDS below) for the handling of parameters (i.e. missing parameters). When the == and != operators are used, the string to the right of the operator is consid‐ ...