06-09-2009
9 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Okay, this probably sounds dumb for anyone who knows the answer, but I'm completely lost. I have to use the head command to search a directory AND all of its subdirectories to display the first line of all .txt files. I know how to do this: head -1 ~/UnixCourse/*.txt, but that does not search the... (4 Replies)
Discussion started by: jbud
4 Replies
2. Shell Programming and Scripting
Hi All,
How can the head command be used to extract only a particular line.
By default head -n filename displays the first n lines. I want only the nth line.
I couldn't get it from forum search.
Thanks,
Sumesh (6 Replies)
Discussion started by: sumesh.abraham
6 Replies
3. UNIX for Dummies Questions & Answers
I am trying to do a head on a mainframe file and on doing ti just gives me a blank screen with nothing on it.
however, when i do a tail for the same file...i get a few lines on the screen.
i know tht mainframe files have all the records on one line...does this have to do something with this.... (10 Replies)
Discussion started by: alfredo123
10 Replies
4. UNIX for Dummies Questions & Answers
Hi friends,I am new to unix and this is really a dummy question.but please help me out.
How to simulate head command without using head command???
also tail command too,also more command.
it is given as a homework to do....please tell me how to do (2 Replies)
Discussion started by: nikhilneela
2 Replies
5. Homework & Coursework Questions
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
I've been stuck on this problem for 2 days now
What command would you enter to list the first lines of all text... (11 Replies)
Discussion started by: partieboi37
11 Replies
6. Shell Programming and Scripting
Hi,
I need some advise on whether there is a better way of doing what I am currently planning to do. Perhaps I should be using arrays instead of re-directing output to files?
I need to use a tool/program named ADRCI provided by Oracle to remove trace files that it generates. Honestly it is... (1 Reply)
Discussion started by: newbie_01
1 Replies
7. Homework & Coursework Questions
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
Write a script that allows the user to print the first n lines or the last n lines of every file in the... (18 Replies)
Discussion started by: lukefrost96
18 Replies
8. Shell Programming and Scripting
we have a file as below
AREA,COUNTRY,RANK
A,MX,1
A,MX,2
A,MX,5
A,MX,8
A,IN,7
A,IN,5
A,IN,21
B,CN,6
B,CN,2
B,CN,8
B,CN,0
we need the TOP 2 RANK records for the combination of Area, Country as below. i know head -2, which gives top 2 records from file but not sure it lists based on... (7 Replies)
Discussion started by: JSKOBS
7 Replies
9. Homework & Coursework Questions
First month learning about the Linux terminal and it has been a challenge yet fun so far. We're learning by using a gameshell. I'm trying to display a certain line ( only allowed 1 command ) from a file only using the head or tail. I'm pretty about this answer:
head -23 history.txt | tail -1... (1 Reply)
Discussion started by: forzatekk
1 Replies
LEARN ABOUT MINIX
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)