Summery
ファイルから、任意の文字を含む行を取得する。Construction
$ grep [option] [value] [file]
Option
-F : string検索（速い） -e : 複数文字列が有る場合 -v : 〜じゃない（逆転判定） -c : 出現回数 -h : ファイル名を同時出力 -m : 行数取得 -x : 行全体を検索対象にする
Sample
# apacheログからiPhoneとAndroidを含む行を検索
$ grep -e iPhone -e Android /var/log/apache2/access.log
# 行に対して完全一致
$ grep -x 'http://exp.com/?a=1' domain.dat
Discription
The grep utility searches any given input files, selecting lines that match one or more
patterns. By default, a pattern matches an input line if the regular expression (RE) in
the pattern matches the input line without its trailing newline. An empty expression
matches every line. Each input line that matches at least one of the patterns is writ-
ten to the standard output.
grep is used for simple patterns and basic regular expressions (BREs); egrep can handle
extended regular expressions (EREs). See re_format(7) for more information on regular
expressions. fgrep is quicker than both grep and egrep, but can only handle fixed pat-
terns (i.e. it does not interpret regular expressions). Patterns may consist of one or
more lines, allowing any of the pattern lines to match a portion of the input.
zgrep, zegrep, and zfgrep act like grep, egrep, and fgrep, respectively, but accept
input files compressed with the compress(1) or gzip(1) compression utilities.
The following options are available:
-A num, --after-context=num
Print num lines of trailing context after each match. See also the -B and -C
options.
-a, --text
Treat all files as ASCII text. Normally grep will simply print ``Binary file
... matches'' if files contain binary characters. Use of this option forces
grep to output lines matching the specified pattern.
-B num, --before-context=num
Print num lines of leading context before each match. See also the -A and -C
options.
-b, --byte-offset
The offset in bytes of a matched pattern is displayed in front of the respective
matched line.
-C[num, --context=num]
Print num lines of leading and trailing context surrounding each match. The
default is 2 and is equivalent to -A 2 -B 2. Note: no whitespace may be given
between the option and its argument.
-c, --count
Only a count of selected lines is written to standard output.
--colour=[when, --color=[when]]
Mark up the matching text with the expression stored in GREP_COLOR environment
variable. The possible values of when can be `never', `always' or `auto'.
-D action, --devices=action
Specify the demanded action for devices, FIFOs and sockets. The default action
is `read', which means, that they are read as if they were normal files. If the
action is set to `skip', devices will be silently skipped.
-d action, --directories=action
Specify the demanded action for directories. It is `read' by default, which
means that the directories are read in the same manner as normal files. Other
possible values are `skip' to silently ignore the directories, and `recurse' to
read them recursively, which has the same effect as the -R and -r option.
-E, --extended-regexp
Interpret pattern as an extended regular expression (i.e. force grep to behave
as egrep).
-e pattern, --regexp=pattern
Specify a pattern used during the search of the input: an input line is selected
if it matches any of the specified patterns. This option is most useful when
multiple -e options are used to specify multiple patterns, or when a pattern
begins with a dash (`-').
--exclude
If specified, it excludes files matching the given filename pattern from the
search. Note that --exclude patterns take priority over --include patterns, and
if no --include pattern is specified, all files are searched that are not
excluded. Patterns are matched to the full path specified, not only to the
filename component.
--exclude-dir
If -R is specified, it excludes directories matching the given filename pattern
from the search. Note that --exclude-dir patterns take priority over
--include-dir patterns, and if no --include-dir pattern is specified, all direc-
tories are searched that are not excluded.
-F, --fixed-strings
Interpret pattern as a set of fixed strings (i.e. force grep to behave as
fgrep).
-f file, --file=file
Read one or more newline separated patterns from file. Empty pattern lines
match every input line. Newlines are not considered part of a pattern. If file
is empty, nothing is matched.
-G, --basic-regexp
Interpret pattern as a basic regular expression (i.e. force grep to behave as
traditional grep).
-H Always print filename headers with output lines.
-h, --no-filename
Never print filename headers (i.e. filenames) with output lines.
--help Print a brief help message.
-I Ignore binary files. This option is equivalent to --binary-file=without-match
option.
-i, --ignore-case
Perform case insensitive matching. By default, grep is case sensitive.
--include
If specified, only files matching the given filename pattern are searched. Note
that --exclude patterns take priority over --include patterns. Patterns are
matched to the full path specified, not only to the filename component.
--include-dir
If -R is specified, only directories matching the given filename pattern are
searched. Note that --exclude-dir patterns take priority over --include-dir
patterns.
-J, --bz2decompress
Decompress the bzip2(1) compressed file before looking for the text.
-L, --files-without-match
Only the names of files not containing selected lines are written to standard
output. Pathnames are listed once per file searched. If the standard input is
searched, the string ``(standard input)'' is written.
-l, --files-with-matches
Only the names of files containing selected lines are written to standard out-
put. grep will only search a file until a match has been found, making searches
potentially less expensive. Pathnames are listed once per file searched. If
the standard input is searched, the string ``(standard input)'' is written.
--mmap Use mmap(2) instead of read(2) to read input, which can result in better perfor-
mance under some circumstances but can cause undefined behaviour.
-m num, --max-count=num
Stop reading the file after num matches.
-n, --line-number
Each output line is preceded by its relative line number in the file, starting
at line 1. The line number counter is reset for each file processed. This
option is ignored if -c, -L, -l, or -q is specified.
--null Prints a zero-byte after the file name.
-O If -R is specified, follow symbolic links only if they were explicitly listed on
the command line. The default is not to follow symbolic links.
-o, --only-matching
Prints only the matching part of the lines.
-p If -R is specified, no symbolic links are followed. This is the default.
-q, --quiet, --silent
Quiet mode: suppress normal output. grep will only search a file until a match
has been found, making searches potentially less expensive.
-R, -r, --recursive
Recursively search subdirectories listed.
-S If -R is specified, all symbolic links are followed. The default is not to fol-
low symbolic links.
-s, --no-messages
Silent mode. Nonexistent and unreadable files are ignored (i.e. their error
messages are suppressed).
-U, --binary
Search binary files, but do not attempt to print them.
-V, --version
Display version information and exit.
-v, --invert-match
Selected lines are those not matching any of the specified patterns.
-w, --word-regexp
The expression is searched for as a word (as if surrounded by `[[:<: ]]' and
`[[:>:]]'; see re_format(7)).
-x, --line-regexp
Only input lines selected against an entire fixed string or regular expression
are considered to be matching lines.
-y Equivalent to -i. Obsoleted.
-Z, -z, --decompress
Force grep to behave as zgrep.
--binary-files=value
Controls searching and printing of binary files. Options are binary, the
default: search binary files but do not print them; without-match: do not search
binary files; and text: treat all files as text.
--context[=num]
Print num lines of leading and trailing context. The default is 2.
--line-buffered
Force output to be line buffered. By default, output is line buffered when
standard output is a terminal and block buffered otherwise.
If no file arguments are specified, the standard input is used.
