His script is taking advantage of the fact that if the action part of a pattern-action pair is missing, the action {print;} is assumed. Further, !p is the same as saying 'p == 0' in the pattern portion of the statement. The value of an undefined variable is either 0 or "" depending on how it is used. To write the script in 'long form' might make more sense to you:
Similarly, printing everything after the pattern line:
i need to use sed to remove an entire line containing a pattern stored in a variable say $var1
this var1 will be a URL and will therefore contain slashes
any help would be greatly appreciated (1 Reply)
Hi all,
I have the following script, but are not too sure about the syntax to complete the script.
In essence, the script must connect to a SFTP server at a client site with username and password located in a file on my server.
Then change to the appropriate directory.
Pull the data to the... (1 Reply)
I have the following:
HH:MM:SS
I want to use either % or # sign to remove :SS can somebody please provide me an example. I know how to do this in awk, but awk is too much
overhead for something this simple since I will be doing this in a loop a lot of times.
Thanks in advance to all... (2 Replies)
Hey Guys!
I have written a code which combines lots of files into one big file(.csv).
However, each of the original files had headers on the first line, and now that I've combined the files the headers are interspersed throughout the new combined data frame. For example, throughout the data... (21 Replies)
I have a binary (hex) file I need to parse to get some data which are encoded this way:
.* b4 . . . 01 12 .* af .* 83 L1 x1 x2 xL 84 L2 y1 y2 yL
By another words there is a stream of hexadecimal bytes (in my example separated by space for better readability). I need to get value stored in... (3 Replies)
I am on ubuntu 11.10 using bash scripts
I want to remove all files matching a string pattern and I am using the following code
find . -name "*$pattern*" -exec rm -f {} \;I have encountered a problem when $pattern is empty. In this case all my files in my current directory were deleted. This... (3 Replies)
Dear team,
I have a file curve.csv which is generated from oracle and each line has a comment associated with it, I want to get rid of this comment, can you please suggest me a command as how to do it
Eg,
cat curve.csv
/*data for today curve*/
/*data for text1*/ this is the header
/*data... (6 Replies)
Hi Everybody! First post! Totally noobie.
I'm using the terminal to read a poorly formatted book.
The text file contains, in the middle of paragraphs, hyphenation to split words that are supposed to be on multiple pages. It looks ve -- ry much like this.
I was hoping to use grep -v " -- "... (5 Replies)
im using the following code to grab data, but after the data in the range im specifying has been grabbed, i want to count how many instances of a particular pattern is found?
awk 'BEGIN{count=0} /parmlib.*RSP/,/seqfiles.*SSD/ {print; count++ } /103 error in ata file/ END { print count }'... (3 Replies)
Discussion started by: SkySmart
3 Replies
LEARN ABOUT DEBIAN
regexp-assemble
REGEXP-ASSEMBLE(1p) User Contributed Perl Documentation REGEXP-ASSEMBLE(1p)NAME
regexp-assemble - Assemble a list of regular expressions from a file
SYNOPSIS
regexp-assemble -abcdfinprsStTuUvw file [...]
DESCRIPTION
Assemble a list of regular expression either from standard input or a file, using the Regexp::Assemble module.
OPTIONS -a look Ahead. Insert "(?=...)" zero-width lookahead assertions in the pattern, where necessary.
-b Blank. Ignore blank lines.
-c Comment. Basic comment filtering. Strip off perl/shell comments ("s*#.*$/").
-d Debug. Turns on debugging output. See Regexp::Assemble for suitable values.
-i Indent. Print the regular expression using and indent of n to display nesting. A.k.a pretty-printing. Implies -p.
-n No newline. Do not print a newline after the pattern. Useful when interpolating the output into a templating system or similar.
-p Print. Print the pattern. This is the default, however, it is required when the -t switch is enabled (because if you want to test
patterns ordinarily you don't care what the the assembled pattern looks like).
-r Reduce. The default behaviour is to reduce the assembled pattern. Enabling this switch causes the reduction algorithm to be switched
off. This can help you determine how much reduction is performed.
regexp-assemble pattern.file | wc
# versus
regexp-assemble -r pattern.file | wc
-s Statistics. Print some statistics about the assembled pattern. The output is sent to STDERR (in order to allow the generated pattern
to be redirected elsewhere).
-S Statistics only. Like -s, except that the pattern itself is not output. Useful with -d 8 to see the time taken.
-t Test. Test the assembled expression against the contents of a file. Each line is read from the file and is matched against the
pattern. Lines that fail to match are printed. In other words, no output is good output. In this mode of operation, error status is 1
in the case of a failure, 0 if all lines matched.
-T Time. Print statistics on the time taken to reduce and assemble the pattern. (This is merely a lazy person's synonym for "-d 8").
-u Unique. Carp if duplicate patterns are found.
-U Unroll. Transform "a+" et al into "aa*" (which may allow additional reductions).
-v Version. Print the version of the regexp-assemble script.
-w Word/Whole. When testing the contents of a file with "-t", bracket the expression with "^" and "$" in order to match the whole word or
line from the file.
DIAGNOSTICS
Will print out a summary of the problem if an added pattern causes the assembly to fail.
SEE ALSO
Regexp::Assemble
AUTHOR
Copyright (C) 2004-2008 David Landgren. All rights reserved.
LICENSE
This script is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
perl v5.14.2 2012-06-30 REGEXP-ASSEMBLE(1p)