SETUID

Section: System Calls (2)
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BSD mandoc
BSD 4.2

NAME

setuid seteuid setgid setegid - set user and group ID

SYNOPSIS

Fd #include <sys/types.h> Fd #include <unistd.h> Ft int Fn setuid uid_t uid Ft int Fn seteuid uid_t euid Ft int Fn setgid gid_t gid Ft int Fn setegid gid_t egid

DESCRIPTION

The Fn setuid function sets the real and effective user IDs and the saved set-user-ID of the current process to the specified value. The Fn setuid function is permitted if the specified ID is equal to the real user ID of the process, or if the effective user ID is that of the super user.

The Fn setgid function sets the real and effective group IDs and the saved set-group-ID of the current process to the specified value. The Fn setgid function is permitted if the specified ID is equal to the real group ID of the process, or if the effective user ID is that of the super user.

The Fn seteuid function (Fn setegid ) sets the effective user ID (group ID) of the current process. The effective user ID may be set to the value of the real user ID or the saved set-user-ID (see intro(2) and execve(2)); in this way, the effective user ID of a set-user-ID executable may be toggled by switching to the real user ID, then re-enabled by reverting to the set-user-ID value. Similarly, the effective group ID may be set to the value of the real group ID or the saved set-user-ID.

RETURN VALUES

Upon success, these functions return 0; otherwise -1 is returned.

If the user is not the super user, or the uid specified is not the real, effective ID, or saved ID, these functions return -1.

STANDARDS

The Fn setuid and Fn setgid functions are compliant with the St -p1003.1-88 specification with _POSIX_SAVED_IDS not defined. The Fn seteuid and Fn setegid functions are extensions based on the POSIX concept of _POSIX_SAVED_IDS and have been proposed for a future revision of the standard.

This document was created by man2html, using the manual pages.
Time: 19:41:53 GMT, December 25, 2022