setresuid.2 (2010 09)

setresuid(2) setresuid(2)

NAME

setresuid, setresgid - set real, effective, and saved user and group IDs

SYNOPSIS

#include <unistd.h>

int setresuid(uid_t ruid, uid_t euid, uid_t suid);

int setresgid(gid_t rgid, gid_t egid, gid_t sgid);

DESCRIPTION

setresuid() sets the real, effective and/or saved user ID of the calling process.

If the current real, effective or saved user ID is equal to that of a user having appropriate privileges,

setresuid() sets the real, effective and saved user IDs to ruid, euid , and suid, respectively. Other-

wise,

setresuid() only sets the real, effective, and saved user IDs if ruid , euid , and suid each match

at least one of the current real, effective, or saved user IDs.

If ruid, euid ,orsuid is

-1, setresuid() leaves the current real, effective or saved user ID

unchanged.

setresgid() sets the real, effective and/or saved group ID of the calling process.

If the current real, effective or saved user ID is equal to that of a user having appropriate privileges,

setresgid() sets the real, effective, and saved group ID to rgid, egid , and sgid, respectively. Other-

wise,

setresgid() only sets the real, effective and saved group ID if rgid, egid, and sgid each match

at least one of the current real, effective or saved group ID.

If rgid, egid,orsgid is

-1, setresgid() leaves the current real, effective or saved group ID

unchanged.

Security Restrictions

Some or all of the actions associated with this system call require the

PRIV_CHSUBJIDENT

privilege

(CHSUBJIDENT). Processes owned by the superuser will have this privilege. Processes owned by other

users may have this privilege, depending on system conﬁguration.

See privileges (5) for more information about privileged access on systems that support ﬁne-grained

privileges.

RETURN VALUE

Upon successful completion,

setresuid() and setresgid() return 0; otherwise, they return − 1

and set errno to indicate the error.

ERRORS

setresuid() and setresgid() fail if any of the following conditions are encountered:

[EINVAL] ruid, euid,orsuid (rgid , egid ,orsgid) is not a valid user (group) ID.

[EPERM] None of the conditions above are met.

AUTHOR

setresuid() and setresgid() were developed by HP.