NAME

setgid − Sets the group ID

SYNOPSIS

#include <unistd.h>

int setgid (
        gid_t group_id );

Application developers may want to specify an #include statement for <sys/types.h> before the one for <unistd.h> if programs are being developed for multiple platforms. The additional #include statement is not required on DIGITAL UNIX systems or by ISO or X/Open standards, but may be required on other vendors’ systems that conform to these standards. 

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

setgid():  POSIX.1, XPG4, XPG4−UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags. 

PARAMETERS

group_idSpecifies the new group ID. 

DESCRIPTION

The setgid() function sets the real group ID, effective group ID, and the saved set group ID to the value specified by the group_id parameter. 

If the process does not have superuser privilege, but the group_id parameter is equal to the real group ID or the saved set group ID, the setgid() function sets the effective group ID to group_id.  The real group ID and saved set group ID remain unchanged. 

Any supplementary group IDs of the calling process remain unchanged. 

RETURN VALUES

Upon successful completion, the setgid() function returns 0 (zero).  Otherwise, the function returns −1 and sets errno to indicate the error. 

ERRORS

The setgid() function sets errno to the specified values for the following conditions:

[EINVAL]The value of the group_id parameter is invalid. 

[EPERM]The process does not have superuser privilege and the group_id parameter does not match the real group ID or the saved set group ID. 

RELATED INFORMATION

Functions: exec(2), getgid(2), setuid(2)

Standards: standards(5)