![Forrest logo](/images/logo.png)
expr:tldr:b34dc
The command "expr match ${string} '${pattern}'" is used to perform pattern matching on a given string using the specified pattern.
Here's an explanation of the command and its components:
-
"${string}": This is a variable that holds the string value on which pattern matching is performed.
-
'${pattern}': This is a variable that holds the pattern to match against the string. The pattern can be specified using regular expressions or simple strings.
-
"expr match": This is the command itself, which is used to perform a pattern matching operation.
The output of this command will be the length of the matched substring if a match is found, or 0 if no match is found. It determines the number of characters at the beginning of the string that match the specified pattern.
Note: The use of single quotes around '${pattern}' is necessary to prevent the shell from expanding any special characters or variables within the pattern.