Difference between revisions of "Exec system call"

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m (Simple use)
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#''-l'' - argv[1] as seen from the executable file
 
#''-l'' - argv[1] as seen from the executable file
 
#''/etc'' - argv[2] as seen from the executable file
 
#''/etc'' - argv[2] as seen from the executable file
#''NULL'' argv[3] as seen from the executable file - end of argument list
+
#''NULL'' - argv[3] as seen from the executable file - end of argument list
 
<source lang=c>
 
<source lang=c>
 
#include <stdio.h>
 
#include <stdio.h>

Revision as of 08:51, 17 December 2022

The exec() family executes a file as a new process. See fork system call for "cloning" a process.

The

Simple use

The execlp() is one of the function call in the exec family. See manpage

The five arguments in the execlp() below is:

  1. ls - the executable file must be in $PATH
  2. ls - argv[0] as seen from the executable file
  3. -l - argv[1] as seen from the executable file
  4. /etc - argv[2] as seen from the executable file
  5. NULL - argv[3] as seen from the executable file - end of argument list
#include <stdio.h>
#include <unistd.h>
int main()
{
        execlp("ls", "ls", "-l", "/etc", NULL);
        return 1;
}