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diff --git a/help/en/bash/grep.html b/help/en/bash/grep.html new file mode 100644 index 0000000..22785fa --- /dev/null +++ b/help/en/bash/grep.html @@ -0,0 +1,301 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> +<head> +<link rel="STYLESHEET" href="../term_tools/main.css" type="text/css"> +<title>grep MAN Page</title> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +</head><!-- #BeginLibraryItem "/Library/head_bash.lbi" --><div id="nav-menu"> +<ul> +<li><a class="rl" href="../term_tools/index.html"><img src="../term_tools/images/ss64.gif" title="Home" alt="Home"></a></li> +<li><a class="rl" href="../term_tools/bash"><img src="../term_tools/images/bash-l.gif" title="bash" alt="bash"></a></li> +<li><!-- Search Google --> +<form action="http://www.google.com/search" method="get" style="margin:0px;padding:0px;"> +<div align="right"> +<input name="q" type="text" class="body" size="25"> +<input class="submit" type="submit" value="Search"> +<input type="hidden" name="q" value="site:ss64.com/bash/"> +</div> +</form></li> +<li><a class="rr" href="syntax.html"><img src="../term_tools/images/syntax-r.gif" title="Bash Syntax"></a></li> +</ul> +</div> <!-- #EndLibraryItem --><h1> grep</h1> +<p>Search file(s) for specific text. </p> +<pre>SYNTAX + grep <<em>options</em>> "<em>Search String</em>" [<em>filename</em>] + + grep <<em>options</em>> [-e <em>pattern</em>] [<em>file</em>...] + + grep <<em>options</em>> [-f <em>file</em>] [<em>file</em>...] + +A simple example: +$grep "Needle in a Haystack" /etc/* + +OPTIONS + +-A <em>NUM</em> +--after-context=<em>NUM</em> + (GNU Extension) + Print <em>NUM</em> lines of trailing context after matching lines. + +-a +--text + (GNU Extension) + Do not suppress output lines that contain binary data. Normally, + if the first few bytes of a file indicate that the file contains + binary data, grep outputs only a message saying that the file + matches the pattern. This option causes grep to act as if the + file is a text file, even if it would otherwise be treated as + binary. _Warning:_ the result might be binary garbage printed to + the terminal, which can have nasty side-effects if the terminal + driver interprets some of it as commands. + +-B <em>NUM</em> +--before-context=<em>NUM</em> + (GNU Extension) + Print NUM lines of leading context before matching lines. + +-b +--byte-offset + (GNU Extension) + Print the byte offset within the input file before each line of + output. When `grep' runs on MS-DOS or MS-Windows, the printed + byte offsets depend on whether the `-u' (`--unix-byte-offsets') + option is used; see below. + +-C <em>NUM</em> +--context=[<em>NUM</em>] + (GNU Extension) + Print NUM lines (default 2) of output context. + +-c +--count + Suppress normal output; instead print a count of matching lines + for each input file. With the `-v', `--invert-match' option, + count non-matching lines. + +-d <em>ACTION</em> +--directories=<em>ACTION</em> + (GNU Extension) + If an input file is a directory, use ACTION to process it. By + default, ACTION is `read', which means that directories are read + just as if they were ordinary files (some operating systems and + filesystems disallow this, and will cause `grep' to print error + messages for every directory). If ACTION is `skip', directories + are silently skipped. If ACTION is `recurse', `grep' reads all + files under each directory, recursively; this is equivalent to the + `-r' option. + +-e <em>PATTERN</em> +--regexp=<em>PATTERN</em> + Use <em>PATTERN</em> as the <a href="../term_tools/bash/grep2.html">pattern</a>; useful to protect patterns beginning + with a - + +-f <em>FILE</em> +--file=<em>FILE</em> + Obtain <a href="../term_tools/bash/grep2.html">patterns</a> from <em>FILE</em>, one per line. The empty file contains + zero patterns, and therefore matches nothing. + +-H +--with-filename + (GNU Extension) + Print the filename for each match. + +-h +--no-filename + (GNU Extension) + Suppress the prefixing of filenames on output when multiple files + are searched. + +--help + (GNU Extension) + Print a usage message briefly summarizing these command-line + options and the bug-reporting address, then exit. + +-i +--ignore-case + Ignore case distinctions in both the pattern and the input files. + +-L +--files-without-match + (GNU Extension) + Suppress normal output; instead print the name of each input file + from which no output would normally have been printed. The + scanning of every file will stop on the first match. + +-l +--files-with-matches + Suppress normal output; instead print the name of each input file + from which output would normally have been printed. The scanning + of every file will stop on the first match. + +--mmap + (GNU Extension) + If possible, ue the `mmap' system call to read input, instead of + the default `read' system call. In some situations, `--mmap' + yields better performance. However, `--mmap' can cause undefined + behavior (including core dumps) if an input file shrinks while + `grep' is operating, or if an I/O error occurs. + +-n +--line-number + Prefix each line of output with the line number within its input + file. + +-<em>NUM</em> + (GNU Extension) + Same as `--context=<em>NUM</em>' lines of leading and trailing context. + However, grep will never print any given line more than once. + +-q +--quiet +--silent + Quiet; suppress normal output. The scanning of every file will + stop on the first match. Also see the `-s' or `--no-messages' + option. + +-r +--recursive + (GNU Extension) + For each directory mentioned in the command line, read and process + all files in that directory, recursively. This is the same as the + `-d recurse' option. + +-s +--no-messages + Suppress error messages about nonexistent or unreadable files. + Portability note: unlike GNU `grep', traditional `grep' did not + conform to POSIX.2, because traditional `grep' lacked a `-q' + option and its `-s' option behaved like GNU `grep''s `-q' option. + Shell scripts intended to be portable to traditional `grep' should + avoid both `-q' and `-s' and should redirect output to `/dev/null' + instead. + +-U +--binary + (GNU Extension) + Treat the file(s) as binary. By default, under MS-DOS and + MS-Windows, `grep' guesses the file type by looking at the + contents of the first 32kB read from the file. If `grep' decides + the file is a text file, it strips the `CR' characters from the + original file contents (to make regular expressions with `^' and + `$' work correctly). Specifying `-U' overrules this guesswork, + causing all files to be read and passed to the matching mechanism + verbatim; if the file is a text file with `CR/LF' pairs at the end + of each line, this will cause some regular expressions to fail. + This option has no effect on platforms other than MS-DOS and + MS-Windows. + +-u +--unix-byte-offsets + (GNU Extension) + Report Unix-style byte offsets. This switch causes `grep' to + report byte offsets as if the file were Unix style text file, + i.e., the byte offsets ignore the `CR' characters which were + stripped. This will produce results identical to running `grep' on + a Unix machine. This option has no effect unless `-b' option is + also used; it has no effect on platforms other than MS-DOS and + MS-Windows. + +-v +--invert-match + Invert the sense of matching, to select non-matching lines. + +-V +--version + (GNU Extension) + Print the version number of `grep' to the standard output stream. + This version number should be included in all bug reports. + +-w +--word-regexp + (GNU Extension) + Select only those lines containing matches that form whole words. + The test is that the matching substring must either be at the + beginning of the line, or preceded by a non-word constituent + character. Similarly, it must be either at the end of the line or + followed by a non-word constituent character. Word-constituent + characters are letters, digits, and the underscore. + +-x +--line-regexp + Select only those matches that exactly match the whole line. + +-Z +--null + (GNU Extension) + Output a zero byte (the ASCII `NUL' character) instead of the + character that normally follows a file name. For example, `grep + -lZ' outputs a zero byte after each file name instead of the usual + newline. This option makes the output unambiguous, even in the + presence of file names containing unusual characters like + newlines. This option can be used with commands like `find + -print0', `perl -0', `sort -z', and `xargs -0' to process + arbitrary file names, even those that contain newline characters. + +-z +--null-data + (GNU Extension) + Treat the input as a set of lines, each terminated by a zero byte + (the ASCII `NUL' character) instead of a newline. Like the `-Z' + or `--null' option, this option can be used with commands like + `sort -z' to process arbitrary file names. + +<b>Environment variables</b> + +Grep's behavior can be affected by setting the following environment variables + +GREP_OPTIONS - default options +LANG - language for messages +POSIXLY_CORRECT - Posix behaviour +_N_GNU_nonoption_argv_flags_ - ignore an operand + +see `info' for more on these +</pre> +<p><span class="body">Grep stands for: Global Regular Expression Print.</span></p> +<p> <b>Diagnostics</b><br> + <br> + Normally, exit status is 0 if matches were found, and 1 if no matches + were found (the `-v' option inverts the sense of the exit status).<br> Exit status is 2 if there were syntax errors in the pattern, +inaccessible input files, or other system errors.</p> +<p><b>Examples</b></p> +<p>Search the file example.txt, including binary data (-a) for the string 'hunting the snark':</p> +<p>$ <span class="code">sudo grep -a 'hunting the snark' example.txt</span></p> +<p>Search the whole partition (/sda1), including binary data(-a) for the string 'hunting the snark' return all the lines starting 25 <b>B</b>efore the text found and 50 lines <b>A</b>fter the matching text found, this can be a way to discover fragments of deleted files but is very slow:</p> +<p>$ <span class="code">grep -a -B 25 -A 50 'hunting the snark' /dev/sda1</span> > results.txt</p> +<p><i>"I understand that change is frightening for people, especially + if there's nothing to go to. It's best to stay where you are. I understand that." - <a href="http://www.bbc.co.uk/politics97/diana/panorama.html">Princess + Diana</a> </i><br> + <br> + <b> Related</b>:<br> + <br> + <a href="egrep.html">egrep</a> - Search file(s) for lines that match an extended + expression<br> + <a href="fgrep.html">fgrep</a> - Search file(s) for lines that match a fixed + string<br> + <a href="awk.html">gawk</a> - Find and Replace text within file(s)<br> + <a href="sed.html">sed</a> - Stream Editor - Find and Replace text within file(s) <br> + <a href="tr.html">tr</a> - Translate, squeeze, and/or delete characters <br> +Equivalent Windows commands: <a href="../term_tools/nt/qgrep.html">QGREP</a> / <a href="../term_tools/nt/findstr.html">FINDSTR</a> - Search for strings in files </p> +<!-- #BeginLibraryItem "/Library/foot_bash.lbi" --><p align="left"><script type="text/javascript"><!-- +google_ad_client = "pub-6140977852749469"; +google_ad_width = 300; +google_ad_height = 250; +google_ad_format = "300x250_as"; +google_ad_type = "text_image"; +google_ad_channel ="1984328893"; +google_color_border = "CCCCCC"; +google_color_bg = "CCCCCC"; +google_color_link = "000000"; +google_color_text = "333333"; +google_color_url = "0000FF"; +//--></script> +<script type="text/javascript" + src="http://pagead2.googlesyndication.com/pagead/show_ads.js"> +</script><br> +</p> +<div align="center"><hr size="1"> + <p id="top"><a href="#"><img src="../term_tools/images/top-4.gif" width="47" height="53" border="0" alt="Back to the Top" title="Back to the Top"></a></p> + <p class="tagline">© Copyright <a href="http://ss64.com/">SS64.com</a> 1999-2010<br> +Some rights reserved<br> +</p> +</div><!-- #EndLibraryItem --></body> +</html> |