...so it would also match adjacent lines. Now I have to figure out how to turn this into a "one-liner" (I currently use "eval" to loop through a file containing pattern matching commands (mostly "sed")) and what each part of the expression does (up until now, my scripting endeavors were limited to rather basic stuff ).
Does anyone know how python compares to other approaches (awk, etc.) in terms of performance? The files I plan to analyze have upwards of 50,000 lines each and are matched against hundreds of single-line and multi-line patterns.
Cheers
Last edited by thefang; 02-25-2014 at 10:37 AM..
Reason: python<>perl mixup
Experts,
I am a beginner to Unix Shell Scripting
We have source as a flat file which contains CTRL+F character as the delimiter. We need to count the number of records in the file (CTRL+F) to perform file validation
Following command being used:
awk '{cnt+=gsub(//,"&")}END {print cnt}'... (4 Replies)
I couldn't figure out how to use sed or any other shell to do the following. Can anyone help? Thanks.
If seeing a string (e.g., TODAY) in the line,
replace a string in the line above (e.g, replace "Raining" with "Sunny")
and replace a string in the line below (e.g., replace "Reading" with... (7 Replies)
I have an xml file that is stripped down to output that looks bacically like;
<!-- TABLEA header -->
<tablea>
some fields
</tablea>
<!-- TABLEB header -->
<!-- TABLEC header -->
<tablec>
some fields
</tablec>
I want to remove the header... (3 Replies)
Sample file:
This is line one,
this is another line,
this is the PRIMARY INDEX line
l ;
This is another line
The command should find the line with “PRIMARY INDEX” and remove the last character from the line preceding it (in this case , comma) and remove the first character from the line... (5 Replies)
Hi friends,
This is sed & awk type question.
I have a text file which has numbers spread all over the file. I want to sum the series of numbers whenever i find it and produce an output file with the sum. For example
###start of input text file ####
abc
def
ghi
1
2
3
4
kjld
random... (3 Replies)
I am trying to find a line in a file ("Replace_Flag") and replace it with a variable which hold a multi lined file.
myVar=`cat myfile`
sed -e 's/Replace_Flag/'$myVar'/' /pathto/test.file
myfile:
cat
dog
boy
girl
mouse
house
test.file:
football
hockey
Replace_Flag
baseball
... (4 Replies)
Hi
I know sed and awk has options to give range of line numbers, but
I need to replace pattern in specific lines
Something like
sed -e '1s,14s,26s/pattern/new pattern/' file name
Can somebody help me in this....
I am fine with see/awk/perl
Thank you in advance (9 Replies)
Hi,
I have a log file which has sessionids in it, each block in the log starts with a date entry, a block may be a single line or multiple lines. I need to sed (or awk) out the lines/blocks with that start with a date and include the session id.
The files are large at several Gb.
My... (3 Replies)
'Hi
I'm using the following code to extract the lines(and redirect them to a txt file) after the pattern match. But the output is inclusive of the line with pattern match.
Which option is to be used to exclude the line containing the pattern?
sed -n '/Conn.*User/,$p' > consumers.txt (11 Replies)
In the awk piped to sed below I am trying to format file by removing the odd xxxx_digits and whitespace after, then move the even xxxx_digit to the line above it and add a space between them. There may be multiple lines in file but they are in the same format. The Filename_ID line is the last line... (4 Replies)
Discussion started by: cmccabe
4 Replies
LEARN ABOUT SUNOS
grep
grep(1)grep(1)NAME
grep - search a file for a pattern
SYNOPSIS
/usr/bin/grep [-bchilnsvw] limited-regular-expression [filename...]
/usr/xpg4/bin/grep [-E | -F] [-c | -l | -q] [-bhinsvwx] -e pattern_list... [-f pattern_file]... [file...]
/usr/xpg4/bin/grep [-E | -F] [-c | -l | -q] [-bhinsvwx] [-e pattern_list...] -f pattern_file... [file...]
/usr/xpg4/bin/grep [-E | -F] [-c | -l | -q] [-bhinsvwx] pattern [file...]
The grep utility searches text files for a pattern and prints all lines that contain that pattern. It uses a compact non-deterministic
algorithm.
Be careful using the characters $, *, [, ^, |, (, ), and in the pattern_list because they are also meaningful to the shell. It is safest
to enclose the entire pattern_list in single quotes '...'.
If no files are specified, grep assumes standard input. Normally, each line found is copied to standard output. The file name is printed
before each line found if there is more than one input file.
/usr/bin/grep
The /usr/bin/grep utility uses limited regular expressions like those described on the regexp(5) manual page to match the patterns.
/usr/xpg4/bin/grep
The options -E and -F affect the way /usr/xpg4/bin/grep interprets pattern_list. If -E is specified, /usr/xpg4/bin/grep interprets pat-
tern_list as a full regular expression (see -E for description). If -F is specified, grep interprets pattern_list as a fixed string. If
neither are specified, grep interprets pattern_list as a basic regular expression as described on regex(5) manual page.
The following options are supported for both /usr/bin/grep and /usr/xpg4/bin/grep:
-b Precedes each line by the block number on which it was found. This can be useful in locating block numbers by context (first block
is 0).
-c Prints only a count of the lines that contain the pattern.
-h Prevents the name of the file containing the matching line from being appended to that line. Used when searching multiple files.
-i Ignores upper/lower case distinction during comparisons.
-l Prints only the names of files with matching lines, separated by NEWLINE characters. Does not repeat the names of files when the
pattern is found more than once.
-n Precedes each line by its line number in the file (first line is 1).
-s Suppresses error messages about nonexistent or unreadable files.
-v Prints all lines except those that contain the pattern.
-w Searches for the expression as a word as if surrounded by < and >.
/usr/xpg4/bin/grep
The following options are supported for /usr/xpg4/bin/grep only:
-e pattern_list Specifies one or more patterns to be used during the search for input. Patterns in pattern_list must be separated by a NEW-
LINE character. A null pattern can be specified by two adjacent newline characters in pattern_list. Unless the -E or -F
option is also specified, each pattern is treated as a basic regular expression. Multiple -e and -f options are accepted
by grep. All of the specified patterns are used when matching lines, but the order of evaluation is unspecified.
-E Matches using full regular expressions. Treats each pattern specified as a full regular expression. If any entire full reg-
ular expression pattern matches an input line, the line is matched. A null full regular expression matches every line.
Each pattern is interpreted as a full regular expression as described on the regex(5) manual page, except for ( and ),
and including:
1. A full regular expression followed by + that matches one or more occurrences of the full regular expression.
2. A full regular expression followed by ? that matches 0 or 1 occurrences of the full regular expression.
3. Full regular expressions separated by | or by a new-line that match strings that are matched by any of the expres-
sions.
4. A full regular expression that is enclosed in parentheses () for grouping.
The order of precedence of operators is [], then *?+, then concatenation, then | and new-line.
-f pattern_file Reads one or more patterns from the file named by the path name pattern_file. Patterns in pattern_file are terminated by a
NEWLINE character. A null pattern can be specified by an empty line in pattern_file. Unless the -E or -F option is also
specified, each pattern is treated as a basic regular expression.
-F Matches using fixed strings. Treats each pattern specified as a string instead of a regular expression. If an input line
contains any of the patterns as a contiguous sequence of bytes, the line is matched. A null string matches every line. See
fgrep(1) for more information.
-q Quiet. Does not write anything to the standard output, regardless of matching lines. Exits with zero status if an input
line is selected.
-x Considers only input lines that use all characters in the line to match an entire fixed string or regular expression to be
matching lines.
The following operands are supported:
file A path name of a file to be searched for the patterns. If no file operands are specified, the standard input is used.
/usr/bin/grep
pattern Specifies a pattern to be used during the search for input.
/usr/xpg4/bin/grep
pattern Specifies one or more patterns to be used during the search for input. This operand is treated as if it were specified as
-e pattern_list.
The -e pattern_list option has the same effect as the pattern_list operand, but is useful when pattern_list begins with the hyphen delim-
iter. It is also useful when it is more convenient to provide multiple patterns as separate arguments.
Multiple -e and -f options are accepted and grep uses all of the patterns it is given while matching input text lines. Notice that the
order of evaluation is not specified. If an implementation finds a null string as a pattern, it is allowed to use that pattern first,
matching every line, and effectively ignore any other patterns.
The -q option provides a means of easily determining whether or not a pattern (or string) exists in a group of files. When searching sev-
eral files, it provides a performance improvement (because it can quit as soon as it finds the first match) and requires less care by the
user in choosing the set of files to supply as arguments (because it exits zero if it finds a match even if grep detected an access or read
error on earlier file operands).
Large File Behavior
See largefile(5) for the description of the behavior of grep when encountering files greater than or equal to 2 Gbyte ( 2**31 bytes).
Example 1: Finding All Uses of a Word
To find all uses of the word "Posix" (in any case) in the file text.mm, and write with line numbers:
example% /usr/bin/grep -i -n posix text.mm
Example 2: Finding All Empty Lines
To find all empty lines in the standard input:
example% /usr/bin/grep ^$
or
example% /usr/bin/grep -v .
Example 3: Finding Lines Containing Strings
All of the following commands print all lines containing strings abc or def or both:
example% /usr/xpg4/bin/grep 'abc
def'
example% /usr/xpg4/bin/grep -e 'abc
def'
example% /usr/xpg4/bin/grep -e 'abc' -e 'def'
example% /usr/xpg4/bin/grep -E 'abc|def'
example% /usr/xpg4/bin/grep -E -e 'abc|def'
example% /usr/xpg4/bin/grep -E -e 'abc' -e 'def'
example% /usr/xpg4/bin/grep -E 'abc
def'
example% /usr/xpg4/bin/grep -E -e 'abc
def'
example% /usr/xpg4/bin/grep -F -e 'abc' -e 'def'
example% /usr/xpg4/bin/grep -F 'abc
def'
example% /usr/xpg4/bin/grep -F -e 'abc
def'
Example 4: Finding Lines with Matching Strings
Both of the following commands print all lines matching exactly abc or def:
example% /usr/xpg4/bin/grep -E '^abc$ ^def$'
example% /usr/xpg4/bin/grep -F -x 'abc def'
See environ(5) for descriptions of the following environment variables that affect the execution of grep: LANG, LC_ALL, LC_COLLATE,
LC_CTYPE, LC_MESSAGES, and NLSPATH.
The following exit values are returned:
0 One or more matches were found.
1 No matches were found.
2 Syntax errors or inaccessible files (even if matches were found).
See attributes(5) for descriptions of the following attributes:
/usr/bin/grep
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
|CSI |Not Enabled |
+-----------------------------+-----------------------------+
/usr/xpg4/bin/grep
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWxcu4 |
+-----------------------------+-----------------------------+
|CSI |Enabled |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
egrep(1), fgrep(1), sed(1), sh(1), attributes(5), environ(5), largefile(5), regex(5), regexp(5), standards(5)
/usr/bin/grep
Lines are limited only by the size of the available virtual memory. If there is a line with embedded nulls, grep only matches up to the
first null. If the line matches, the entire line is printed.
/usr/xpg4/bin/grep
The results are unspecified if input files contain lines longer than LINE_MAX bytes or contain binary data. LINE_MAX is defined in
/usr/include/limits.h.
23 May 2005 grep(1)
02-25-2014
).