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Working of exec family of functions

 
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# 6  
Old 05-13-2013
I consider that code dangerous because, when exec fails, the child code will fall into that same loop and start making its own child processes, which will start making their own child processes -- a forkbomb. Always put an exit() after your exec()'s, just in case!

Code:
for(index = 0; index < SOME_MAX_VAL;index++)
{
  pid = fork();
  if( pid > 0 )
    continue;
  else
  {
    exec(SOME_EXECUTABLE,index);
    perror("exec failed");
    exit(1);
  }
}

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LEARN ABOUT OSX

getexecname

getexecname(3C) 					   Standard C Library Functions 					   getexecname(3C)

NAME

       getexecname - return pathname of executable

SYNOPSIS

       #include <stdlib.h>

       const char *getexecname(void);

DESCRIPTION

       The  getexecname() function returns the pathname (the first argument of one of the exec family of functions; see exec(2)) of the executable
       that started the process.

       Normally this is an absolute pathname, as the majority of commands are executed by the shells that append the command name  to  the  user's
       PATH  components.   If this is not an absolute path, the output of getcwd(3C) can be prepended to it to create an absolute path, unless the
       process or one of its ancestors has changed its root directory or current working directory since the last successful call to  one  of  the
       exec family of functions.

RETURN VALUES

       If successful, getexecname() returns a pointer to the executables pathname; otherwise, it returns 0.

USAGE

       The getexecname() function obtains the executable pathname from the AT_SUN_EXECNAME aux vector.	These vectors are made available to dynam-
       ically linked processes only.

       A successful call to one of the exec family of functions will always have AT_SUN_EXECNAME in the aux vector.  The  associated  pathname	is
       guaranteed to be less than or equal to PATH_MAX, not counting the trailing null byte that is always present.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       exec(2), getcwd(3C), attributes(5)

SunOS 5.10							    17 Dec 1997 						   getexecname(3C)