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Full Discussion: exec() system call
Top Forums Programming exec() system call Post 47093 by a25khan on Monday 2nd of February 2004 08:13:38 PM
Old 02-02-2004
exec() system call

hi there,
i was reading about the exec() function. and if i m not wrong, exec() kills your present process and starts a new process in its place. the process id remains the same.
then it says if exec is successful the text data and stack are overlayed by new file! -
i dont get this part "only user area is maintained across exec system call"
can someone tell me what the user area is in particular? like what part of a program would be user area!?
Thank You!
 

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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)
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