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Full Discussion: C: error in wait system call
Top Forums Programming C: error in wait system call Post 302580772 by tafazzi87 on Friday 9th of December 2011 01:55:19 PM
Old 12-09-2011
Quote:
Originally Posted by fpmurphy
What OS and version are you on? Cygwin? What compiler version are you using and how are you compiling this program?
i use gcc 4.6.1 under ubuntu 11.10

Quote:
Originally Posted by Corona688
When something expects a "int *", you're not supposed to declare an "int *". That creates an empty pointer, pointing to nowhere, which will probably cause your program to crash when used!

What they want when they demand an "int *" is pointer to an integer, the address of an integer, so they can modify that integer.

Code:
int stat;

wait(&stat);

thanks a lot i solved this problem Smilie
 

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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)
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