rgrep-a recursive, highlighting grep program

rgrep ”a recursive, highlighting grep program

 rgrep [ options] pattern [file] ...... 

rgrep , unlike grep and egrep , can recursively descend directories. The traditional way of performing this kind of search on UNIX systems utilizes the find command in conjunction with grep . Using rgrep results in much better performance. See also xargs command.

COMMAND-LINE OPTIONS:

-?	Additional help (use -? to avoid shell expansion on some systems).
-c	Count matches.
-h	Highlight match (ANSI-compatible terminal assumed).
-H	Output match instead of entire line containing match.
-i	Ignore case.
-l	List filename only.
-n	Print line number of match.
-F	Follow links.
-r	Recursively scan through directory tree.
-N	Do NOT perform a recursive search.
-R pat	Like -r except that only those files matching pat are checked.
-v	Print only lines that do NOT match the specified pattern.
-x ext	Check only files with extension given by ext .
-D	Print all directories that would be searched. This option is for debugging purposes only. No file is grepped with this option.
-W len	Lines are len characters long (not newline terminated ).

SUPPORTED REGULAR EXPRESSIONS:

.	Matches any character except newline.
\d	Matches any digit.
\e	Matches ESC char.
*	Matches zero or more occurrences of previous RE.
+	Matches one or more occurrences of previous RE.
?	Matches zero or one occurrence of previous RE.
^	Matches beginning of line.
$	Matches end of line.
[ ... ]	Matches any single character between brackets. For example, [-02468] matches - or any even digit, and [-0-9a-z] matches - and any digit between 0 and 9 as well as letters a through z.
\{ ...\}	Used for repetition; e.g., x\{9\} matches nine x characters
\( ...\)	Used for backreferencing. Pattern in \(...\) is tagged and saved. Starting at the left-hand side of the regular expression, allowed up to nine tags. To restore saved pattern, \1, \2 ... \9 are used.
\2 \1, =, ...., \9	Matches match specified by n th \( ... \) expression. For example, \([ \t][a-zA-Z]+\)\1[ \t] matches any word repeated consecutively.

Example A.45.

 1  rgrep -n -R '*.c' '^int'  2  rgrep -n -xc '^int'  

EXPLANATION

1. Look in all files with a "c" extension in current directory and all its subdirectories looking for matches of "int" at the beginning of a line, printing the line containing the match with its line number.

2. Look in all files with a ".c" extension, printing the line beginning with "int" and preceded with its line number. (Same as above.)