The grep command in Linux
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15.02.2023, 17:28
The grep command in UNIX-like operating systems is used to search for a given substring or regular expression in text files or the output of other commands.
What function does the grep command perform
The syntax of the grep command is as follows:
grep [options] template [files]
Here, the template is the substring or regular expression you are looking for, and [files] is a list of files to search in. If [files] are not specified, then grep will read the input data from the standard input (this usually means that you can pass the output of other commands to grep).
Some common grep options:
-i - ignore case of characters when searching-r - search recursively in all subdirectories-n - output the line numbers in which the template is found-v - output only lines that do not contain a template
For example, to find all the lines in a file example.txt containing the word "apple", you can use the command:
grep apple example.txt
And to find all the files in the current directory and its subdirectories containing the word "banana", you can use the command:
grep -r banana .
There 's a point here . means the current directory.
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