Bash, short for "Bourne Again SHell," is a powerful scripting language used in Unix-based operating systems. One of the fundamental constructs in Bash programming is the if statement. The if statement allows you to control the flow of your script based on specific conditions. In this article,...
including if, else, and elif. Then we'll look at a few of the "primary" operators you can leverage in a conditional statement such as = for string equality, -eq for numeric equality, and -e to check if a file exists. After that, we'll use conditional statements...
else statement... fi 注意关键字then可以换行起,但我个人还是喜欢放在同一行。 条件表达式 conditional-expression -nSTRINGThelength ofSTRINGisgreater than zero.-zSTRINGThelengh ofSTRINGiszero(ie itisempty).STRING1=STRING2STRING1isequaltoSTRING2STRING1!=STRING2STRING1isnotequaltoSTRING2INTEGER1-eqINTEGER...
[ n1 -ne n2 ] (true if n1 is not same as n2, else false) [ n1 -gt n2 ] (true if n1 greater then n2, else false) [ n1 -lt n2 ] (true if n1 less then n2, else false) String Comparisons: = - is equal to - if [ "$a" = "$b" ] == - is equal to - if [ "$...
Example 3: If statement in bash on less than a number In addition to-eqfor equality you can also try-lt -le -gt -getest conditions for less than, less than or equal, greater than or greater then or equal respectively. Below is a similar example with less then operator-lt: ...
If the exit status is not equal to zero, the ‘else’ block is executed, which prints a message indicating that the command has failed. Here’s a simple example to illustrate how we can use an ‘if’ statement to check the exit status of a command: ...
How to check if a string is in an array? How to use the Bash ternary operator? How to negate an if condition in a Bash if statement? (if not command or if not equal) How to use the BASH_REMATCH variable with the Regular Expression Operator =~?
The syntax of the "if" statement in Bash is as follows: if[condition]then# code to be executed if condition is trueelse# code to be executed if condition is falsefi Negating the "if" condition To negate the "if" condition, the logical operator!(NOT) is used. It reverses the logical...
If two strings are equal in a Bash script, it implies that both strings have the same length and character sequence. The “if” statement is used to check Bash strings for equality. Comparison with “==” operators To check if two strings are equal in a Bash script, there are two ...
-ne: Not equal -lt: Less than -le: Less than or equal to -gt: Greater than -ge: Greater than or equal to In following bash script example, we are comparing two numbers using if condition statement. #!/bin/bash echo "Enter the Number: " ...