One of the most common operations when working with strings in Bash is to determine whether or not a string contains another string. In this article, we will show you several ways to check if a string contains a substring.
_repeat() { #@ USAGE: _repeat string number _REPEAT=$1 while (( ${#_REPEAT} < $2 )) ## Loop until string exceeds desired length do _REPEAT=$_REPEAT$_REPEAT$_REPEAT ## 3 seems to be the optimum number done _REPEAT=${_REPEAT:0:$2} ## Trim to desired length } repeat() { ...
string1 != string2 - The inequality operator returns true if the operands are not equal. string1 =~ regex- The regex operator returns true if the left operand matches the extended regular expression on the right.string1 > string2 - The greater than operator returns true if the left operand...
I have had so many instances where I wanted to check if a value was present in an array or not. You can probably iterate over all the array items and check it individually, but what if I give you the red pill? I have created an array in which there is a stringasdfand I want to...
How does Bash string end in Linux? Find out it here. This article has the best methods of how to check with what bash string ends. Here you will also find out freeware software to transfer Linux files on Windows.
Use regex on a stringThe result of bash's regex matching can be used to replace sed for a large number of use-cases.CAVEAT: This is one of the few platform dependent bash features. bash will use whatever regex engine is installed on the user's system. Stick to POSIX regex features if...
An array 'phone_numbers' is created to hold various phone numbers to be tested against the regex. Function definition: test_phone_number function: Take a phone number as an argument. Check if the phone number matches the 'regex'. Prints "Match" if the phone number is valid, otherwise prin...
In addition to logical flags there are also logical operators. One of the most useful logical operators is the regex match operator=~. The regex match operator compares a string to a regular expression and if the string is a match for the regex then the expression is equivalent totrue, othe...
if [[ STRING1 =~ REGEXPATTERN ]]; then This statement works only with double-bracket syntax. This condition is true only if the string named ‘STRING1’ matches with the REGEXPPATTERN. Arithmetic or Number-Based Bash If Conditions if [ NUM1 -eq NUM2 ]; then The condition is true ...
string is null -n string is not null Regular Expressions Regular expressions are shortened as ‘regexp' or ‘regex'. They are strings of characters that define a search pattern. It can be used as a search or search & replace operation. Expressions Explanation . Matches any single character....