[unix-history] / usr / src / usr.bin / grep / egrep / grep.1

.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)grep.1	4.1 (Berkeley) %G%
.\"
.TH GREP 1 8/11/80
.UC 4
.SH NAME
grep, egrep, fgrep \- search a file for a pattern
.SH SYNOPSIS
.B grep
[ option ] ...
expression [ file ] ...
.LP
.B egrep 
[ option ] ...
[ expression ]
[ file ] ...
.PP
.B fgrep
[ option ] ...
[ strings ]
[ file ]
.SH DESCRIPTION
Commands of the
.I grep
family search the input
.I files
(standard input default)
for lines matching
a pattern.
Normally, each line found
is copied to the standard output.
.I Grep
patterns are limited regular expressions in the style of
.IR ex (1);
it uses a compact nondeterministic algorithm.
.I Egrep
patterns are full regular expressions;
it uses a fast deterministic algorithm that
sometimes needs exponential space.
.I Fgrep
patterns are fixed strings; it is fast and compact.
The following options are recognized.
.TP
.B \-v
All lines but those matching
are printed.
.TP
.B \-x
(Exact) only lines matched in their entirety are printed
.RI ( fgrep
only).
.TP
.B \-c
Only a count of matching lines is printed.
.TP
.B \-l
The names of files with matching lines are listed (once)
separated by newlines.
.TP
.B \-n
Each line is preceded by
its relative line number in the file.
.TP
.B \-b
Each line is preceded by the block number
on which it was found.
This is sometimes useful in locating
disk block numbers by context.
.TP
.B \-i
The case of letters is ignored in making comparisons.
(E.g. upper and lower case are considered identical.)
(\fIgrep\fR\| and \fIfgrep\fR only)
.TP
.B \-s
Silent mode.
Nothing is printed (except error messages).
This is useful for checking the error status.
.TP
.B \-w
The expression is searched for as a word
(as if surrounded by `\e<' and `\e>', see
.IR ex (1).)
(\fIgrep\fR\| only)
.TP
.BI \-e " expression"
Same as a simple
.I expression 
argument,
but useful when the
.I expression
begins with a \-.
.TP
.BI \-f " file"
The regular expression
.RI ( egrep )
or string list
.RI ( fgrep ) 
is taken from the
.I file.
.PP
In all cases the file name is shown if there is more than one input file.
Care should be taken when
using the characters
$ * [ ^ | ( ) and \\ in the
.I expression
as they are
also meaningful to the Shell.
It is safest to enclose the
entire
.I expression
argument in single quotes \' \'.
.PP
.I Fgrep
searches for lines that contain one of the (newline-separated)
.I strings.
.PP
.I Egrep
accepts extended regular expressions.
In the following description `character' excludes
newline:
.IP
A \e followed by a single character
other than newline
matches that character.
.IP
The character ^ ($) matches the beginning (end) of
a line.
.IP
A 
.B .
matches any character.
.IP
A single character not otherwise endowed with special
meaning matches that character.
.IP
A string enclosed in brackets [\|]
matches any single character from the string.
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.
.IP
A regular expression followed by * (+, ?) matches a sequence
of 0 or more (1 or more, 0 or 1)
matches of the regular expression.
.IP
Two regular expressions concatenated
match a match of the first followed by a match of 
the second.
.IP
Two regular expressions separated by | or newline
match either a match for the first or a match for the
second.
.IP
A regular expression enclosed in parentheses
matches a match for the regular expression.
.LP
The order of precedence of operators
at the same parenthesis level
is [\|] then
*+? then concatenation then | and newline.
.SH "SEE ALSO"
ex(1),
sed(1),
sh(1)
.SH DIAGNOSTICS
Exit status is 0 if any matches are found,
1 if none, 2 for syntax errors or inaccessible files.
.SH BUGS
Ideally there should be only one
.I grep,
but we don't know a single algorithm that spans a wide enough
range of space-time tradeoffs.
.PP
Lines
are limited to 256 characters;
longer lines are truncated.
Commit	Line	Data
732dc260 KM	1	.\" Copyright (c) 1980 Regents of the University of California.
	2	.\" All rights reserved. The Berkeley software License Agreement
	3	.\" specifies the terms and conditions for redistribution.
	4	.\"
	5	.\" @(#)grep.1 4.1 (Berkeley) %G%
	6	.\"
	7	.TH GREP 1 8/11/80
	8	.UC 4
	9	.SH NAME
	10	grep, egrep, fgrep \- search a file for a pattern
	11	.SH SYNOPSIS
	12	.B grep
	13	[ option ] ...
	14	expression [ file ] ...
	15	.LP
	16	.B egrep
	17	[ option ] ...
	18	[ expression ]
	19	[ file ] ...
	20	.PP
	21	.B fgrep
	22	[ option ] ...
	23	[ strings ]
	24	[ file ]
	25	.SH DESCRIPTION
	26	Commands of the
	27	.I grep
	28	family search the input
	29	.I files
	30	(standard input default)
	31	for lines matching
	32	a pattern.
	33	Normally, each line found
	34	is copied to the standard output.
	35	.I Grep
	36	patterns are limited regular expressions in the style of
	37	.IR ex (1);
	38	it uses a compact nondeterministic algorithm.
	39	.I Egrep
	40	patterns are full regular expressions;
	41	it uses a fast deterministic algorithm that
	42	sometimes needs exponential space.
	43	.I Fgrep
	44	patterns are fixed strings; it is fast and compact.
	45	The following options are recognized.
	46	.TP
	47	.B \-v
	48	All lines but those matching
	49	are printed.
	50	.TP
	51	.B \-x
	52	(Exact) only lines matched in their entirety are printed
	53	.RI ( fgrep
	54	only).
	55	.TP
	56	.B \-c
	57	Only a count of matching lines is printed.
	58	.TP
	59	.B \-l
	60	The names of files with matching lines are listed (once)
	61	separated by newlines.
	62	.TP
	63	.B \-n
	64	Each line is preceded by
65	its relative line number in the file.
66	.TP
67	.B \-b
68	Each line is preceded by the block number
69	on which it was found.
70	This is sometimes useful in locating
71	disk block numbers by context.
72	.TP
73	.B \-i
74	The case of letters is ignored in making comparisons.
75	(E.g. upper and lower case are considered identical.)
76	(\fIgrep\fR\\| and \fIfgrep\fR only)
77	.TP
78	.B \-s
79	Silent mode.
80	Nothing is printed (except error messages).
81	This is useful for checking the error status.
82	.TP
83	.B \-w
84	The expression is searched for as a word
85	(as if surrounded by `\e<' and `\e>', see
86	.IR ex (1).)
87	(\fIgrep\fR\\| only)
88	.TP
89	.BI \-e " expression"
90	Same as a simple
91	.I expression
92	argument,
93	but useful when the
94	.I expression
95	begins with a \-.
96	.TP
97	.BI \-f " file"
98	The regular expression
99	.RI ( egrep )
100	or string list
101	.RI ( fgrep )
102	is taken from the
103	.I file.
104	.PP
105	In all cases the file name is shown if there is more than one input file.
106	Care should be taken when
107	using the characters
108	$ * [ ^ \| ( ) and \\ in the
109	.I expression
110	as they are
111	also meaningful to the Shell.
112	It is safest to enclose the
113	entire
114	.I expression
115	argument in single quotes \' \'.
116	.PP
117	.I Fgrep
118	searches for lines that contain one of the (newline-separated)
119	.I strings.
120	.PP
121	.I Egrep
122	accepts extended regular expressions.
123	In the following description `character' excludes
124	newline:
125	.IP
126	A \e followed by a single character
127	other than newline
128	matches that character.
129	.IP
130	The character ^ ($) matches the beginning (end) of
131	a line.
132	.IP
133	A
134	.B .
135	matches any character.
136	.IP
137	A single character not otherwise endowed with special
138	meaning matches that character.
139	.IP
140	A string enclosed in brackets [\\|]
141	matches any single character from the string.
142	Ranges of ASCII character codes may be abbreviated
143	as in `a\-z0\-9'.
144	A ]
145	may occur only as the first character of the string.
146	A literal \- must be placed where it can't be
147	mistaken as a range indicator.
148	.IP
149	A regular expression followed by * (+, ?) matches a sequence
150	of 0 or more (1 or more, 0 or 1)
151	matches of the regular expression.
152	.IP
153	Two regular expressions concatenated
154	match a match of the first followed by a match of
155	the second.
156	.IP
157	Two regular expressions separated by \| or newline
158	match either a match for the first or a match for the
159	second.
160	.IP
161	A regular expression enclosed in parentheses
162	matches a match for the regular expression.
163	.LP
164	The order of precedence of operators
165	at the same parenthesis level
166	is [\\|] then
167	*+? then concatenation then \| and newline.
168	.SH "SEE ALSO"
169	ex(1),
170	sed(1),
171	sh(1)
172	.SH DIAGNOSTICS
173	Exit status is 0 if any matches are found,
174	1 if none, 2 for syntax errors or inaccessible files.
175	.SH BUGS
176	Ideally there should be only one
177	.I grep,
178	but we don't know a single algorithm that spans a wide enough
179	range of space-time tradeoffs.
180	.PP
181	Lines
182	are limited to 256 characters;
183	longer lines are truncated.