signal handler for SIGCHLD Post: 77010

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Hi. I have a program whose job it is to manage 15 child processes. Sometimes these children die (sometimes deliberately other times with a SEGV). This causes a SIGCHLD to be sent to my program which uses waitpid() in the signal handler to gather information and, in most cases, restart the child....

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LEARN ABOUT MINIX

ppmtopgm

ppmtopgm(1)                                                   General Commands Manual                                                  ppmtopgm(1)

NAME

       ppmtopgm - convert a portable pixmap into a portable graymap

SYNOPSIS

       ppmtopgm [ppmfile]

DESCRIPTION

       Reads  a  portable  pixmap  as  input.  Produces a portable graymap as output.  The output is a "black and white" rendering of the original
       image, as in a black and white photograph.  The quantization formula used is .299 r + .587 g + .114 b.

       Note that although there is a pgmtoppm program, it is not necessary for simple conversions from pgm to ppm , because any  ppm  program  can
       read  pgm  (and  pbm  ) files automatically.  pgmtoppm is for colorizing a pgm file.  Also, see ppmtorgb3 for a different way of converting
       color to gray.  And ppmdist generates a grayscale image from a color image, but in a way that makes it easy to differentiate  the  original
       colors, not necessarily a way that looks like a black and white photograph.

QUOTE

       Cold-hearted orb that rules the night
       Removes the colors from our sight
       Red is gray, and yellow white
       But we decide which is right
       And which is a quantization error.

SEE ALSO

       pgmtoppm(1),ppmtorgb3(1),rgb3toppm(1),ppmdist(1),ppm(5),pgm(5)

AUTHOR

       Copyright (C) 1989 by Jef Poskanzer.

                                                                   10 April 2000                                                       ppmtopgm(1)

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

shell script signal handler

Discussion started by: jalburger

2. UNIX for Advanced & Expert Users

catch SIGCHLD signal in parent process

Discussion started by: ranjan

3. Programming

signal handler problems

Discussion started by: blowtorch

4. Programming

Runaway SIGALRM signal handler

Discussion started by: stewartw