.TH CHMOD 2 .CT 2 file_inq_creat dirs secur .SH NAME chmod, fchmod, chown, fchown, utime \(mi change file mode, owner, group, or times .SH SYNOPSIS .nf .B int chmod(file, mode) .B char *name; .PP .B int fchmod(fildes, mode) .PP .B int chown(file, uid, gid) .B char *name; .PP .B int fchown(fildes, uid, gid) .PP .B #include <sys/types.h> .PP .B int utime(file, timep) .B char *file; .B time_t timep[2]; .fi .SH DESCRIPTION These functions change inode information for the file named by a null-terminated string or associated with file descriptor .IR fildes . .PP .I Chmod and .I fchmod change file permissions and other mode bits to .IR mode . Mode values are defined in .IR stat (2). Only the .B 07777 bits of .IR mode are significant. Only the owner of a file (or super-user) may change the mode. Only a process in the file's group (or super-user) may set the set-group-id bit, .BR S_ISGID . .PP .I Chown and .I fchown change the owner, .I uid, and the group, .I gid, of a file. Only the super-user may change a file's owner. The owner of a file may change its group to match the current effective groupid. Other changes are restricted to the super-user. .PP .I Utime sets the .B st_atime (access time) and .B st_mtime (modify time) fields for .I file to .B timep[0] and .B timep[1] respectively. The .B st_ctime (inode change time) field for .I file is set to the current time. .PP The caller must be the owner of the file or the super-user. .SH "SEE ALSO" .IR stat (2), .IR time (2) .SH DIAGNOSTICS all: .BR EIO , .BR EPERM .br .IR "chmod, chown, utime" : .BR ELOOP , .BR ENOENT , .BR ENOTDIR , .BR EACCES , .B EFAULT .br .IR "fchmod, fchown" : .B EBADF .SH BUGS An attempt to change the inode data for a file on a read-only file system is quietly ignored.