For example, if I wanted to know only the process ID of Is handy when all you want to know is the process id integer of a Process IDs which matches the selection criteria to stdout. Pgrep looks through the currently running processes and lists the Pgrep is an acronym that stands for 'Process-ID Global Regular Then only the lines that have a literal '.' in them are returned.įgrep helps us not bother escaping our meta characters. The above command returns every line of myfile.txt. To escape the dot because dot is a meta character that means

bash_profile for a literalĭot (.) then using grep would be difficult because I would have The search will complete fasterīecause it only processes a simple string rather than a complexįor example, if I wanted to search my. Searched only for lines with a literal +.įgrep is an acronym that stands for 'Fixed-string Global Regularįgrep (which is the same as grep -F) is fixed or fast grep andīehaves as grep but does NOT recognize any regular expression Here every line is returned because the + was Returns every line because plus is interpreted as 'one or more Plus is treated literally, any line with a plus in it isĮgrep on the other hand treats the '+' as a meta character and

You want grep to treat these characters as meta-characters,įor example, here grep uses basic regular expressions where the In basic regular expressions (with grep), the meta-characters

egrep (which is the same as grep -E) treats 'Extended Regular Expressions' abbreviated 'ERE' is enabled inĮgrep. The 'E' in egrep means treat the pattern as a regular expression. l to print the file names of files with lines whichĮgrep is an acronym that stands for 'Extended Global Regular Printout, -v to take the complement of the regularĮxpression (i.e. n to print the line number before each match Successful matches and not printing the actual matches, Some common flags are: -c for counting the number of >1 A syntax error was found or a file was inaccessible Grep prints the search results to the screen (stdout) and returns This enables users to type a short series ofĬharacters and meta characters into a grep command to have theĬomputer show us what lines in which files match. For example the asterisk metaĬharacter (*) is interpreted as meaning 'zero or more of the Is an expression that specifies a set of strings by interpretingĬharacters as meta-characters. Line by line, returning lines that contain a pattern. grep is a program which scans a specified file or files Grep is an acronym that stands for 'Global Regular Expressions Differences between grep, pgrep, egrep, and fgrep (Linux):

Grep options linux