1. grep（global search regular expression(RE) and print out theline,全面搜索正则表达式并把行打印出来）是一种强大的文本搜索工具，它能使用正则表达式搜索文本，并把匹配的行打印出来。
2. 主要问题还是在正则式的应用上
可以参考 用到的 正则表达式
3. –help看细节:
Example: grep -i ‘hello world’ menu.h main.cRegexp selection and interpretation: -E, –extended-regexp PATTERN is an extended regular expression (ERE) -F, –fixed-strings PATTERN is a set of newline-separated fixed strings -G, –basic-regexp PATTERN is a basic regular expression (BRE) -P, –perl-regexp PATTERN is a Perl regular expression -e, –regexp=PATTERN use PATTERN for matching -f, –file=FILE obtain PATTERN from FILE 从文件中读取搜索模式 -i, –ignore-case ignore case distinctions -w, –word-regexp force PATTERN to match only whole words -x, –line-regexp force PATTERN to match only whole lines -z, –null-data a data line ends in 0 byte, not newlineMiscellaneous: -s, –no-messages suppress error messages -v, –invert-match select non-matching lines -V, –version print version information and exit –help display this help and exit –mmap use memory-mapped input if possibleOutput control: -m, –max-count=NUM stop after NUM matches -b, –byte-offset print the byte offset with output lines -n, –line-number print line number with output lines –line-buffered flush output on every line -H, –with-filename print the filename for each match -h, –no-filename suppress the prefixing filename on output –label=LABEL print LABEL as filename for standard input -o, –only-matching show only the part of a line matching PATTERN -q, –quiet, –silent suppress all normal output –binary-files=TYPE assume that binary files are TYPE; TYPE is `binary’, `text’, or `without-match’ -a, –text equivalent to –binary-files=text -I equivalent to –binary-files=without-match 只输出文件名 -d, –directories=ACTION how to handle directories; 用来忽略目录 ACTION is `read’, `recurse’, or `skip’ -D, –devices=ACTION how to handle devices, FIFOs and sockets; ACTION is `read’ or `skip’ -R, -r, –recursive equivalent to –directories=recurse 递归搜索子目录
下面几个有助于在指定类型的文件中查找 –include=FILE_PATTERN search only files that match FILE_PATTERN –exclude=FILE_PATTERN skip files and directories matching FILE_PATTERN –exclude-from=FILE skip files matching any file pattern from FILE –exclude-dir=PATTERN directories that match PATTERN will be skipped. -L, –files-without-match print only names of FILEs containing no match -l, –files-with-matches print only names of FILEs containing matches -c, –count print only a count of matching lines per FILE -T, –initial-tab make tabs line up (if needed) -Z, –null print 0 byte after FILE nameContext control: 上下文控制 -B, –before-context=NUM print NUM lines of leading context -A, –after-context=NUM print NUM lines of trailing context -C, –context=NUM print NUM lines of output context -NUM same as –context=NUM –color[=WHEN], –colour[=WHEN] use markers to highlight the matching strings; WHEN is `always’, `never’, or `auto’ -U, –binary do not strip CR characters at EOL (MSDOS) -u, –unix-byte-offsets report offsets as if CRs were not there (MSDOS)`egrep’ means `grep -E’. `fgrep’ means `grep -F’.
参考:
1. http://man.chinaunix.net/newsoft/grep/open.htm
2.
因为它抚平了心底的不安;当你尝到了极品的美食，
