string="This is a test string."# Define the substringsubstring="test"# Check if the string contains the substringifecho"$string"| grep -q"$substring"thenecho"Substring found."elseecho"Substring not found."fi As we expected, theifstatement will return"Substring found."as the target string$s...
So, you have a long string and you want to check of this string contains a substring in your bash script. There are more than one way to check for substrings in bash shell. I'll show some simple examples first, followed by a cool bash script that uses this concept in a real-world ...
/bin/bash## Name: test-bucket-1## Purpose:# Performs the test-bucket number 1 for Product X.# (Actually, this is a sample shell script,# which invokes some system commands# to illustrate how to construct a Bash script)## Notes:# 1) The environment variable TEST_VAR must be set# (...
How to check if a string is in an array? How to use the Bash ternary operator? How to negate an if condition in a Bash if statement? (if not command or if not equal) How to use the BASH_REMATCH variable with the Regular Expression Operator =~?
如果if结构使用的不是test命令,而是普通命令,比如上一节的((...))算术运算,或者test命令与普通命令混用,那么可以使用 Bash 的命令控制操作符&&(AND)和||(OR),进行多个命令的逻辑运算。$ command1 && command2 $ command1 || command2对于&&操作符,先执行command1,只有command1执行成功后, 才会执行command2。
-n is one of the supported bash string comparison operators used for checking null strings in a bash script. When -n operator is used, it returns true for every case, but that’s if the string contains characters. On the other hand, if the string is empty, it won’t return true. ...
The following output appears if the script is executed with the string input value: Using the “If -N” Statement Sometimes, it is required to check if a string variable is non-empty or if it contains a string value more than zero length. There are many options in Bash to do this task...
To prove that, below is the output one gets from running this script: Found the number 5 Method 2: Use grep to see if array contains value If it is too hard for you to remember what the regex operator is (I can understand, it was hard for me to remember in the beginning too), ...
$ var="Welcome to Baeldung" $ if [[ $var =~ [A-Z] ]]; then echo "String contains an uppercase letter." else echo "String does not contain an uppercase letter." fi String contains an uppercase letter. So, we used a variablevarcontainingWelcome to Baeldung. Next, we interpolatedvar...
To check if a Bash array contains a value, use the echo command and pipe it to grep command to search the value from the defined array.