...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 REDHAT
pcregrep
PCREGREP(1) General Commands Manual PCREGREP(1)NAME
pcregrep - a grep with Perl-compatible regular expressions.
SYNOPSIS
pcregrep [-Vcfhilnrsvx] pattern [file] ...
DESCRIPTION
pcregrep searches files for character patterns, in the same way as other grep commands do, but it uses the PCRE regular expression library
to support patterns that are compatible with the regular expressions of Perl 5. See pcre(3) for a full description of syntax and semantics.
If no files are specified, pcregrep reads the standard input. By default, each line that matches the pattern is copied to the standard out-
put, and if there is more than one file, the file name is printed before each line of output. However, there are options that can change
how pcregrep behaves.
Lines are limited to BUFSIZ characters. BUFSIZ is defined in <stdio.h>. The newline character is removed from the end of each line before
it is matched against the pattern.
OPTIONS -V Write the version number of the PCRE library being used to the standard error stream.
-c Do not print individual lines; instead just print a count of the number of lines that would otherwise have been printed. If sev-
eral files are given, a count is printed for each of them.
-ffilename
Read patterns from the file, one per line, and match all patterns against each line. There is a maximum of 100 patterns. Trailing
white space is removed, and blank lines are ignored. An empty file contains no patterns and therefore matches nothing.
-h Suppress printing of filenames when searching multiple files.
-i Ignore upper/lower case distinctions during comparisons.
-l Instead of printing lines from the files, just print the names of the files containing lines that would have been printed. Each
file name is printed once, on a separate line.
-n Precede each line by its line number in the file.
-r If any file is a directory, recursively scan the files it contains. Without -r a directory is scanned as a normal file.
-s Work silently, that is, display nothing except error messages. The exit status indicates whether any matches were found.
-v Invert the sense of the match, so that lines which do not match the pattern are now the ones that are found.
-x Force the pattern to be anchored (it must start matching at the beginning of the line) and in addition, require it to match the
entire line. This is equivalent to having ^ and $ characters at the start and end of each alternative branch in the regular
expression.
SEE ALSO pcre(3), Perl 5 documentation
DIAGNOSTICS
Exit status is 0 if any matches were found, 1 if no matches were found, and 2 for syntax errors or inacessible files (even if matches were
found).
AUTHOR
Philip Hazel <ph10@cam.ac.uk>
Last updated: 15 August 2001
Copyright (c) 1997-2001 University of Cambridge.
PCREGREP(1)
02-25-2014
).