09-21-2010
10 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
I know we can substitute a string using sed but how?
For example: sed 's/(old variable)/(new variable)/ details.dat
Am I suppose to put $old variable or whatever? Because I tried many times, it didnt work by putting $old variable. Am I suppose to enclose it with "" or ''?
Please help (3 Replies)
Discussion started by: Ohji
3 Replies
2. Shell Programming and Scripting
When I run the script I pass in 2 expressions (ex. replace.ksh new old)
I want the script to go line by line for a given file in a given directory and replace the word new with old. Of course in my line where I have the awk statement it is replacing the 2nd word with 1st instead of new with... (3 Replies)
Discussion started by: goodrics
3 Replies
3. Shell Programming and Scripting
Hi ,
I am stuck up in the below scenario:-
I need to read a file name (eg A.txt) name frm another file (eg B.txt) and then I need to search for a particular expression in A.txt and substitute it with another expression.
How can I use SED inside SHELL Scripting and command prompt as... (2 Replies)
Discussion started by: shubhranshu
2 Replies
4. Shell Programming and Scripting
Hi ,
I am stuck up in the below scenario:-
I need to read a file name (eg A.txt) name frm another file (eg B.txt) and then I need to search for a particular expression in A.txt and substitute it with another expression.
How can I use SED inside SHELL Scripting and command prompt as well to... (1 Reply)
Discussion started by: shubhranshu
1 Replies
5. Shell Programming and Scripting
Hi guys,
Can u please help me to replace (-) with (/) in a file containing no of records using "sed " command in unix.
thanks in advance.
subhendu (5 Replies)
Discussion started by: subhendu81
5 Replies
6. Shell Programming and Scripting
I have file.txt
1 4 7 9 3
I want to replace the tabs with a space, but my code doesn't work.
cat file.txt | sed 's/"\t"/ /g' > t.txt
But file is still the same. Numbers seperated by tabs instead of spaces.
Help? (2 Replies)
Discussion started by: Bandit390
2 Replies
7. Shell Programming and Scripting
Hi I am trying to do a text insertion in a text file at a particular line number in a shell script. However its not working.
sed '122i\
> for j in \`echo $MyList\` ; do perl -pi -e\'s#01\/01\/2009#01\/01\/2011#\' $j ; done' $HOME/MyScript.ksh
The Actual line to be inserted at line 122... (5 Replies)
Discussion started by: som.nitk
5 Replies
8. Shell Programming and Scripting
I have a file with some numbers having single quotes around them which I want to remove.
i.e. '923930' -> 23930
If it can be done without using sed thats fine. I have tried with sed but can't think how to replace this pattern on only the numbers (13 Replies)
Discussion started by: user_invalid
13 Replies
9. UNIX for Dummies Questions & Answers
Hello to all. I'm new to this forum, so please go easy on me. =)
I am working on a script to send two e-mail attachments in a single e-mail, and am running into a little bit of an issue when using process substitution. I am using the following:
cat <(uuencode $1 <(basename $1)) <(uuencode... (5 Replies)
Discussion started by: rommager
5 Replies
10. Shell Programming and Scripting
Hi everyone,
I need very simple sed command to change a parameter in a text file.
I have a line in this text which is like
set xx 0.5
A program reads this file and does some algebraic calculations. So to make a parameter scan I need to change the value of xx. I thought I can do... (7 Replies)
Discussion started by: hayreter
7 Replies
LEARN ABOUT REDHAT
pbmreduce
pbmreduce(1) General Commands Manual pbmreduce(1)
NAME
pbmreduce - read a portable bitmap and reduce it N times
SYNOPSIS
pbmreduce [-floyd|-fs|-threshold ] [-value val] N [pbmfile]
DESCRIPTION
Reads a portable bitmap as input. Reduces it by a factor of N, and produces a portable bitmap as output.
pbmreduce duplicates a lot of the functionality of pgmtopbm; you could do something like pnmscale | pgmtopbm, but pbmreduce is a lot
faster.
pbmreduce can be used to "re-halftone" an image. Let's say you have a scanner that only produces black&white, not grayscale, and it does a
terrible job of halftoning (most b&w scanners fit this description). One way to fix the halftoning is to scan at the highest possible res-
olution, say 300 dpi, and then reduce by a factor of three or so using pbmreduce. You can even correct the brightness of an image, by
using the -value flag.
OPTIONS
By default, the halftoning after the reduction is done via boustrophedonic Floyd-Steinberg error diffusion; however, the -threshold flag
can be used to specify simple thresholding. This gives better results when reducing line drawings.
The -value flag alters the thresholding value for all quantizations. It should be a real number between 0 and 1. Above 0.5 means darker
images; below 0.5 means lighter.
All flags can be abbreviated to their shortest unique prefix.
SEE ALSO
pnmenlarge(1), pnmscale(1), pgmtopbm(1), pbm(5)
AUTHOR
Copyright (C) 1988 by Jef Poskanzer.
02 August 1989 pbmreduce(1)