FindList

FindList["file","text"] gives a list of lines in the file that contain the specified string.

• FindList["file",{"text1","text2",…}] gives a list of all lines that contain any of the specified strings.
• FindList[{"file1",…},…] gives a list of lines containing the specified strings in any of the filei.
• FindList[files,text,n] includes only the first n lines found.

Examples

(* Find all lines containing "error" *)
FindList["log.txt", "error"]

(* Find lines with multiple patterns *)
FindList["data.txt", {"warning", "error", "critical"}]

(* Get only first 10 matches *)
FindList["bigfile.txt", "pattern", 10]

Please visit the official Wolfram Language Reference for more details.