egrep - search a file for a pattern using full regular expressions
/usr/bin/egrep [-bchilnsv] -e pattern_list [file...]
/usr/bin/egrep [-bchilnsv] -f file [file...]
/usr/bin/egrep [-bchilnsv] pattern [file...]
/usr/xpg4/bin/egrep [-bchilnqsvx] -e pattern_list [-f file] [file...]
/usr/xpg4/bin/egrep [-bchilnqsvx] [-e pattern_list] -f file [file...]
/usr/xpg4/bin/egrep [-bchilnqsvx] pattern [file...]
The egrep (expression grep) utility searches files for a pattern of characters and prints all lines that contain that pattern. egrep uses full regular expressions (expressions that have string values that use the full set of alphanumeric and special characters) to match the patterns. It uses a fast deterministic algorithm that sometimes needs exponential space.
If no files are specified, egrep assumes standard input. Normally, each line found is copied to the standard output. The file name is printed before each line found if there is more than one input file.
The /usr/bin/egrep utility accepts full regular expressions as described on the regexp(5) manual page, except for \( and \), \( and \), \{ and \}, \< and \>, and \n, and with the addition of:
Be careful using the characters $, *, [, ^, |, (, ), and \ in full regular expression, because they are also meaningful to the shell. It is safest to enclose the entire full regular expression in single quotes (a'a').
The order of precedence of operators is [], then *?+, then concatenation, then | and NEWLINE.
The /usr/xpg4/bin/egrep utility uses the regular expressions described in the EXTENDED REGULAR EXPRESSIONS section of the regex(5) manual page.
The following options are supported for both /usr/bin/egrep and /usr/xpg4/bin/egrep:
-b
-c
-e pattern_list
-f file
-h
-i
-l
-n
-s
-v
The following options are supported for /usr/xpg4/bin/egrep only:
-q
-x
The following operands are supported:
file
pattern
pattern
See largefile(5) for the description of the behavior of egrep when encountering files greater than or equal to 2 Gbyte ( 2^31 bytes).
See environ(5) for descriptions of the following environment variables that affect the execution of egrep: LC_COLLATE, LC_CTYPE, LC_MESSAGES, and NLSPATH.
The following exit values are returned:
0
1
2
See attributes(5) for descriptions of the following attributes:
|
|
fgrep(1), grep(1), sed(1), sh(1), attributes(5), environ(5), largefile(5), regex(5), regexp(5), XPG4(5)
Ideally there should be only one grep command, but there is not a single algorithm that spans a wide enough range of space-time trade-offs.
Lines are limited only by the size of the available virtual memory.
The /usr/xpg4/bin/egrep utility is identical to /usr/xpg4/bin/grep -E. See grep(1). Portable applications should use /usr/xpg4/bin/grep -E.
Закладки на сайте Проследить за страницей |
Created 1996-2024 by Maxim Chirkov Добавить, Поддержать, Вебмастеру |