tablelink: window = gtk_window_new (GTK_WINDOW_TOPLEVEL) $ # trying grep -R without passing tablelink explicitly Tablelink: window = gtk_window_new (GTK_WINDOW_TOPLEVEL) $ # passing tablelink on the command line buttons.c: window = gtk_window_new (GTK_WINDOW_TOPLEVEL) $ # not passing tablelink explicitly on the command line With the -R option, grep always follows the symbolic link. In case of the -r option, grep follows the symbolic link only if it has been specifically passed on the command line. The difference between the -r and -R options is the handling of symbolic links. New/wind.c: gtk_container_set_border_width (GTK_CONTAINER (window), 10) New/wind.c: gtk_window_set_title (GTK_WINDOW (window), 'Searching Buffers') New/wind.c: window = gtk_window_new (GTK_WINDOW_TOPLEVEL)

For example,īuttons.c: window = gtk_window_new (GTK_WINDOW_TOPLEVEL) That is, if a file in that directory is again a directory, it searches in files in it and so on. If an input file is a directory and the -r option is used, grep searches pattern recursively in files in that directory. Gtk_window_set_title (GTK_WINDOW (window), 'Searching Buffers') Window = gtk_window_new (GTK_WINDOW_TOPLEVEL)

With the -i option, you can ask grep to ignore case and do case insensitive search. The -E option is for extended regular expressions. R is matched at least n times but not more than m times ( grep -E only)Įither r1 or r2 is matched. R is matched at most m times ( grep -E only) R is matched at least n times ( grep -E only) R is matched exactly n times ( grep -E only) R is matched zero or 1 time ( grep -E only) R is matched 1 or more times ( grep -E only) One of the blank characters (space and tab).Īny one of the control characters (for ASCII, octal 000 through octal 037, and octal 177 (DEL)).Īny one of the hexadecimal digits (0-9 and a-f) : ? ^ _ ` ~)Īny one of the graphical characters (from the union of ] and ])Īny one of the space characters (for C locale and ASCII character encoding, from tab, newline, vertical tab, form feed, carriage return, and space).Īny one of the printable characters (] and space). Ranges like a-e are OK.Īny one of the lowercase letters (for C locale and ASCII character coding, a-z).Īny one of the uppercase letters (for C locale and ASCII character coding, A-Z).Īny one of the alphabetic characters (from the union of ] and ]).Īny one of the alphanumeric characters (from the union of ] and ]).Īny one of the punctuation characters (for C locale and ASCII character coding, from ! ' # $ % & ' ( ) * +,.

Grep - Regular Expressions Regular ExpressionĪny character, c, except for special characters, matches itself.įor any special character, c, the meaning is turned off and c is matched.Īny one of the characters inside brackets. Let's look at some of the regular expressions, listed in the decreasing order of precedence below. It should print all lines containing the search string. This works in the vi editor as well, just try the command, :g/ regular-expression/p in vi on a Linux system, substituting regular-expression with a search string. re is a regular expression between two slashes and p is the command to print all lines that match the regular expression. In one of the earliest text editor made available on UNIX systems, ed, the g command is the global command, for all lines in the file. If we we look closely at the grep command name, we see g re p. So, if the input has a string from the set associated with a regular expression, we get a match. A regular expression matches a set of strings. A regular expression is a pattern with certain metacharacters having special meanings. The pattern, mentioned above, is a regular expression. Gtk_box_pack_start (GTK_BOX (vbox), hbox, FALSE, TRUE, 0) Gtk_box_pack_start (GTK_BOX (hbox), find, FALSE, TRUE, 0) Gtk_box_pack_start (GTK_BOX (hbox), w -> entry, TRUE, TRUE, 0)

GtkWidget *window, *scrolled_win, *hbox, *vbox, *find It searches the files for the pattern and prints the lines that contain strings matching the pattern. Grep is a program for searching a given string pattern in files.

Grep usage in linux