setegid()
Set the effective group ID for a process
Synopsis:
#include <unistd.h>
int setegid( gid_t gid );
Arguments:
- gid
- The effective group ID that you want to use for the process.
Library:
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
Description:
The setegid() function lets the calling process set the effective group ID based on the following:
- If the process has the PROCMGR_AID_SETGID ability enabled (see procmgr_ability()), the setegid() function sets the effective group ID to gid.
- If the process doesn't have the PROCMGR_AID_SETGID ability enabled, but gid is equal to the real group ID or saved set-group ID, setegid() sets the effective group ID to gid.
The real and saved group ID aren't changed.
If a set-group ID process sets its effective group ID to its real
group ID, it can still set its effective group ID back to the saved
set-group ID.
Returns:
Zero for success, or -1 if an error occurs (errno is set).
Errors:
- EINVAL
- The value of gid is out of range.
- EPERM
- The process doesn't have the PROCMGR_AID_SETGID ability enabled, and gid doesn't match the real group ID or the saved set-group ID.
Examples:
/*
* This process sets its effective group ID to 2
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
int main( void )
{
gid_t oegid;
oegid = getegid();
if( setegid( 2 ) == -1 ) {
perror( "setegid" );
return EXIT_FAILURE;
}
printf( "Was effective group %d, is 2\n", oegid );
return EXIT_SUCCESS;
}
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | Yes |
| Thread | Yes |