_O_n_l_i_n_e _M_a_n_u_a_l User Commands grep(1) NNNNAAAAMMMMEEEE grep, egrep, fgrep - search a file for a pattern SSSSYYYYNNNNTTTTAAAAXXXX ggggrrrreeeepppp [ option ] ... expression [ file ] ... eeeeggggrrrreeeepppp [ option ] ... [ expression ] [ file ] ... ffffggggrrrreeeepppp [ option ] ... [ strings ] [ file ] DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN Commands of the _g_r_e_p family search the input _f_i_l_e_s (standard input default) for lines matching a pattern. Normally, each line found is copied to the standard output. _g_r_e_p patterns are limited regular expressions in the style of _e_x(1); it uses a compact nondeterministic algorithm. _e_g_r_e_p patterns are full regular expressions; it uses a fast deterministic algorithm that sometimes needs exponential space. _f_g_r_e_p patterns are fixed strings; it is fast and compact. The following options are recognized. ----vvvv All lines but those matching are printed. ----xxxx (Exact) only lines matched in their entirety are printed (_f_g_r_e_p only). ----cccc Only a count of matching lines is printed. ----llll The names of files with matching lines are listed (once) separated by newlines. ----nnnn Each line is preceded by its relative line number in the file. ----bbbb Each line is preceded by the block number on which it was found. This is sometimes useful in locating disk block numbers by context. ----hhhh Suppresses printing of file names when there is more than one input file. ----iiii The case of letters is ignored in making comparisons - that is, upper and lower case are considered identical. This applies to _g_r_e_p and _f_g_r_e_p only. ----ssss Silent mode. Nothing is printed (except error mes- sages). This is useful for checking the error status. ----wwww The expression is searched for as a word (as if sur- rounded by `\<' and `\>', see _e_x(1).) (_g_r_e_p only) ----eeee _e_x_p_r_e_s_s_i_o_n Same as a simple _e_x_p_r_e_s_s_i_o_n argument, but useful when the _e_x_p_r_e_s_s_i_o_n begins with a -. ----ffff _f_i_l_e The regular expression (_e_g_r_e_p) or string list (_f_g_r_e_p) is taken from the _f_i_l_e. In all cases the file name is shown if there is more than one input file (except when the ----hhhh option is used). Care should be taken when using the characters $ * [ ^ | ( ) and \ in the _e_x_p_r_e_s_s_i_o_n as they are also meaningful to the Shell. It is safest to enclose the entire _e_x_p_r_e_s_s_i_o_n argu- ment in single quotes ' '. _f_g_r_e_p searches for lines that contain one of the (newline- separated) _s_t_r_i_n_g_s. _e_g_r_e_p accepts extended regular expressions. In the follow- ing description `character' excludes newline: A \ followed by a single character other than newline matches that character. The character ^ matches the beginning of a line. The character $ matches the end of a line. A .... (period) matches any character. A single character not otherwise endowed with special meaning matches that character. A string enclosed in brackets [] matches any single character in the string (or not in the string if pre- ceded by ^). Ranges of ASCII character codes may be abbreviated as in `a-z0-9'. A ] may occur only as the first character of the string. A literal - must be placed where it can't be mistaken as a range indicator. A regular expression followed by an * (asterisk) matches a sequence of 0 or more matches of the regular expression. A regular expression followed by a + (plus) matches a sequence of 1 or more matches of the regular expression. A regular expression followed by a ? (question mark) matches a sequence of 0 or 1 matches of the regular expression. Two regular expressions concatenated match a match of the first followed by a match of the second. Two regular expressions separated by | or newline match either a match for the first or a match for the second. A regular expression enclosed in parentheses matches a match for the regular expression. The order of precedence of operators at the same parenthesis level is [] then *+? then concatenation then | and newline. Ideally there should be only one _g_r_e_p, but we don't know a single algorithm that spans a wide enough range of space- time tradeoffs. SSSSEEEEEEEE AAAALLLLSSSSOOOO User Commands (1): ex, sed, sh DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS Exit status is 0 if any matches are found, 1 if none, 2 for syntax errors or inaccessible files. MMMMEEEESSSSSSSSAAAAGGGGEEEESSSS grep: unknown flag You specified an option which _g_r_e_p doesn't recog- nize. Check the manual page above for the options. grep: argument too long The regular expression is currently limited to 251 characters. You will have to simplify the expres- sion. grep: RE error You have made a mistake in specifying the regular expression. For instance, a pattern such as the following indicates a badly formed regular expres- sion. % ggggrrrreeeepppp ''''[[[[^^^^]]]]'''' ssssoooommmmeeeeffffiiiilllleeee grep: can't open _f_i_l_e_n_a_m_e _g_r_e_p cannot access the file specified by _f_i_l_e_n_a_m_e. Check that the filename is spelled correctly, or that you have read permission for that file. grep RE botch This means that _g_r_e_p is confused. This implies an internal error in the program. LLLLIIIIMMMMIIIITTTTAAAATTTTIIIIOOOONNNNSSSS Lines are limited to 256 characters; longer lines are trun- cated. January 1990 TX User's Reference