Replace what you want with something easily matchable, delete what you don't want, and restore it. This avoids needing strange convolution, backreferences, or non-greedy matching.
Another method would be splitting on RR45, changing all non-blank tokens into "%", then imploding again.
Hello,
from the gnu sed manual, I should be able to do this:
`\(REGEXP\)'
Groups the inner REGEXP as a whole, this is used to:
* Apply postfix operators, like `\(abcd\)*': this will search
for zero or more whole sequences of `abcd', while `abcd*'
... (3 Replies)
Hi there, I need to test that a variable ($VAR) matches a regex mask in BASH. I have the exact thing working in perl (below), but could somebody advise me how i would do the same in BASH ? do i need to use something like egrep ?
#!/bin/perl -w
my $VAR = "some value";
if ( $VAR =~... (4 Replies)
Why is only hello3 being printed? There must be some kind of syntax problem because the file list definitely includes all the file extensions line by line.
#!/bin/bash
find '/home/myuser/folder/' -name '*.c' -type f | while read F
do
if ] # if the file name ends in .txt.c
then
... (6 Replies)
I am having trouble parsing rpm filenames in a shell script.. I found a snippet of perl code that will perform the task but I really don't have time to rewrite the entire script in perl. I cannot for the life of me convert this code into something sed-friendly:
if ($rpm =~ /(*)-(*)-(*)\.(.*)/)... (1 Reply)
Hi,
I'm trying to validate if a string matches a regular expression, but it is not working. Am I missing something? Do I need to scape any of the characters?
if echo 'en-GB' | egrep '({1,8})(-{1,8})*' >/dev/null; then
echo Valid value
fi
Thanks in advance (6 Replies)
Hi ,
I am trying to extract contents of a file between specified time stamp. but it does not seem to work. i am trying to extract output of /var/adm/messages between 15:00:00 to 15:23:59 .
i have tried two regex the first one seems to kind of work. it displays some output. the second one is... (13 Replies)
I have a number of files that I pass through awk/gsub.
I believe to have found a working regex and on 'test bed' sites it matches, however within gsub it does not.
Examples:
Initial data:
/Volumes/Daniel/Public/Drop Box/_Hellsing_Ultimate_OVA_-_10_.mkv
gsub & regex:
gsub("\]+\]",""
... (4 Replies)
I am not a big expert in regex and have just little understanding of that language.
Could you help me to understand the regular Perl expression:
^(?!if\b|else\b|while\b|)(?:+?\s+){1,6}(+\s*)\(*\) *?(?:^*;?+){0,10}\{
------
This is regex to select functions from a C/C++ source and defined in... (2 Replies)
Discussion started by: alex_5161
2 Replies
LEARN ABOUT MINIX
pnmconvol
pnmconvol(1) General Commands Manual pnmconvol(1)NAME
pnmconvol - general MxN convolution on a portable anymap
SYNOPSIS
pnmconvol convolutionfile [pnmfile]
DESCRIPTION
Reads two portable anymaps as input. Convolves the second using the first, and writes a portable anymap as output.
Convolution means replacing each pixel with a weighted average of the nearby pixels. The weights and the area to average are determined by
the convolution matrix. The unsigned numbers in the convolution file are offset by -maxval/2 to make signed numbers, and then normalized,
so the actual values in the convolution file are only relative.
Here is a sample convolution file; it does a simple average of the nine immediate neighbors, resulting in a smoothed image:
P2
3 3
18
10 10 10
10 10 10
10 10 10
To see how this works, do the above-mentioned offset: 10 - 18/2 gives 1. The possible range of values is from 0 to 18, and after the off-
set that's -9 to 9. The normalization step makes the range -1 to 1, and the values get scaled correspondingly so they become 1/9 - exactly
what you want. The equivalent matrix for 5x5 smoothing would have maxval 50 and be filled with 26.
The convolution file will usually be a graymap, so that the same convolution gets applied to each color component. However, if you want to
use a pixmap and do a different convolution to different colors, you can certainly do that.
At the edges of the convolved image, where the convolution matrix would extend over the edge of the image, pnmconvol just copies the input
pixels directly to the output.
SEE ALSO pnmsmooth(1), pnm(5)AUTHORS
Copyright (C) 1989, 1991 by Jef Poskanzer.
Modified 26 November 1994 by Mike Burns, burns@chem.psu.edu
26 November 1994 pnmconvol(1)