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SETREUID(2)              DragonFly System Calls Manual             SETREUID(2)


setreuid -- set real and effective user ID's


Standard C Library (libc, -lc)


#include <unistd.h> int setreuid(uid_t ruid, uid_t euid);


The real and effective user IDs of the current process are set according to the arguments. If ruid or euid is -1, the current uid is filled in by the system. Unprivileged users may change the real user ID to the effec- tive user ID and vice-versa; only the super-user may make other changes. The setreuid() function has been used to swap the real and effective user IDs in set-user-ID programs to temporarily relinquish the set-user-ID value. This purpose is now better served by the use of the seteuid() function (see setuid(2)). When setting the real and effective user IDs to the same value, the stan- dard setuid() function is preferred.


The setreuid() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.


[EPERM] The current process is not the super-user and a change other than changing the effective user-id to the real user-id was specified.


getuid(2), issetugid(2), seteuid(2), setuid(2)


The setreuid() system call appeared in 4.2BSD. DragonFly 3.5 February 8, 2001 DragonFly 3.5

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