I am not saying it is his fault that I do not understand it. I am the one asking for help, but he went on the give me an example of using execl using a built-in command(date) when I specifically said in the OP that I already have been given an example of using execl with a command ("The only example done in class by the professor was calling the ps command which is a command and not a script.") when I'm trying to figure out how to use it with calling a script I have made myself. He then proceeded to tell me to pay attention to what I'm doing which irked me because I feel like I'm paying quite a bit of attention to what I'm doing.
With that said, thanks for pointing out my typo.
Where you say it needs the name of the file, are you saying I should do this?...
Because, I do have the name of the file in the second argument already.
---------- Post updated at 12:26 PM ---------- Previous update was at 12:19 PM ----------
OKAY, got it.
Changed it to:
And it ran my a7.sh script. Although, it printed my output twice in both the parent and child class. Not sure if that's how it's supposed to be, but at least it's running the script which is the main thing I wanted. Thanks.
This User Gave Thanks to miniviking10 For This Post:
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Discussion started by: Freaky123
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LEARN ABOUT LINUX
varargs
varargs(3EXT) Extended Library Functions varargs(3EXT)NAME
varargs - handle variable argument list
SYNOPSIS
#include <varargs.h>
va_alist
va_dcl
va_list pvar;
void va_start(va_listpvar);
type va_arg(va_list pvar, type);
void va_end(va_list pvar);
DESCRIPTION
This set of macros allows portable procedures that accept variable argument lists to be written. Routines that have variable argument lists
(such as printf(3C)) but do not use varargs are inherently non-portable, as different machines use different argument-passing conventions.
va_alist is used as the parameter list in a function header.
va_dcl is a declaration for va_alist. No semicolon should follow va_dcl.
va_list is a type defined for the variable used to traverse the list.
va_start is called to initialize pvar to the beginning of the list.
va_arg will return the next argument in the list pointed to by pvar. type is the type the argument is expected to be. Different types can
be mixed, but it is up to the routine to know what type of argument is expected, as it cannot be determined at runtime.
va_end is used to clean up.
Multiple traversals, each bracketed by va_start and va_end, are possible.
EXAMPLES
Example 1: A sample program.
This example is a possible implementation of execl (see exec(2) ).
#include <unistd.h>
#include <varargs.h>
#define MAXARGS 100
/* execl is called by
execl(file, arg1, arg2, ..., (char *)0);
*/
execl(va_alist)
va_dcl
{
va_list ap;
char *file;
char *args[MAXARGS]; /* assumed big enough*/
int argno = 0;
va_start(ap);
file = va_arg(ap, char *);
while ((args[argno++] = va_arg(ap, char *)) != 0)
;
va_end(ap);
return execv(file, args);
}
SEE ALSO exec(2), printf(3C), vprintf(3C), stdarg(3EXT)NOTES
It is up to the calling routine to specify in some manner how many arguments there are, since it is not always possible to determine the
number of arguments from the stack frame. For example, execl is passed a zero pointer to signal the end of the list. printf can tell how
many arguments are there by the format.
It is non-portable to specify a second argument of char, short, or float to va_arg, since arguments seen by the called function are not
char, short, or float. C converts char and short arguments to int and converts float arguments to double before passing them to a function.
stdarg is the preferred interface.
SunOS 5.10 10 May 2002 varargs(3EXT)