In GNU grep, there is no difference in available functionality between basic and extended syntaxes. In other implementations, basic regular expressions are less powerful.

Jun 16, 2013 · -E is for extended regular expressions, formerly provided by egrep, but -e is not for basic regular expressions; it simply specifies that the following argument is (one of) the regular …

In the synopsis's first form, which is used if no -e or -f options are present, the first operand PATTERNS is one or more patterns separated by newline characters, and grep prints each …

Nov 14, 2025 · grep is a command-line utility in Linux used for searching text. It searches for lines that match a given pattern and outputs those lines. The name grep comes from the ed …

Aug 2, 2007 · The grep utilities are a family that includes grep, grep -E (formally egrep), and grep -F (formally fgrep) for searching files. For most use cases, fgrep is sufficient due to speed and …

Nov 3, 2025 · The grep command is one of the most useful tools in Linux and Unix systems. It is used to search for specific words, phrases, or patterns inside text files, and shows the …

grep is a command-line utility for searching text for lines that match a regular expression. Its name comes from the ed command g/ re /p (g lobal, r egular e xpression, p rint), which has the same …

grep searches the input files for lines containing a match to a given pattern list. When it finds a match in a line, it copies the line to standard output (by default), or whatever other sort of …

Without the -e, grep might treat the pattern as an option if it begins with ‘ - ’. Without the ‘./ ’, there might be similar problems with file names beginning with ‘ - ’.

Dec 23, 2024 · grep enables you to search for the given pattern not just in one but multiple files. Here’s how you can look for a pattern in multiple files by using * wildcard.