Unix/Linux系統調用
accept()函數 Unix/Linux
access()函數 Unix/Linux
acct()函數 Unix/Linux
add_key()函數 Unix/Linux
adjtimex()函數 Unix/Linux
afs_syscall()函數 Unix/Linux
alarm()函數 Unix/Linux
alloc_hugepages()函數 Unix/Linux
arch_prctl()函數 Unix/Linux
bdflush()函數 Unix/Linux
bind()函數 Unix/Linux
break未實現 Unix/Linux
brk()函數 Unix/Linux
cacheflush()函數 Unix/Linux
chdir()函數 Unix/Linux
chmod()函數 Unix/Linux
chown()函數 Unix/Linux
chroot()函數 Unix/Linux
clone()函數 Unix/Linux
close()函數 Unix/Linux
connect()函數 Unix/Linux
create_module()函數 Unix/Linux
open()函數 Unix/Linux
dup2()函數 Unix/Linux
dup()函數 Unix/Linux
epoll_create()函數 Unix/Linux
epoll_ctl()函數 Unix/Linux
epoll_wait()函數 Unix/Linux
execve()函數 Unix/Linux
exit_group函數 Unix/Linux
_exit()函數 Unix/Linux
exit()函數 Unix/Linux
faccessat()函數 Unix/Linux
fattach()函數 Unix/Linux
fchdir()函數 Unix/Linux
fchmodat()函數 Unix/Linux
fchmod()函數 Unix/Linux
fchownat()函數 Unix/Linux
fchown()函數 Unix/Linux
fcntl()函數 Unix/Linux
fdatasync()函數 Unix/Linux
fdetach()函數 Unix/Linux
flock()函數 Unix/Linux
fork()函數 Unix/Linux
alloc_hugepages()函數 Unix/Linux
fstatat()函數 Unix/Linux
statfs()函數 Unix/Linux
stat()函數 Unix/Linux
statvfs()函數 Unix/Linux
fsync()函數 Unix/Linux
truncate()函數 Unix/Linux
futex()函數 Unix/Linux
futimesat()函數 Unix/Linux
getcontext()函數 Unix/Linux
getcwd()函數 Unix/Linux
getdents()函數 Unix/Linux
getdomainname()函數 Unix/Linux
getdtablesize()函數 Unix/Linux
getgid()函數 Unix/Linux
getuid()函數 Unix/Linux
getgroups()函數 Unix/Linux
getgroups()函數 Unix/Linux
gethostname()函數 Unix/Linux
getitimer()函數 Unix/Linux
get_kernel_syms()函數 Unix/Linux
unimplemented()函數 Unix/Linux
getpagesize()函數 Unix/Linux
getpeername()函數 Unix/Linux
setpgid()函數 Unix/Linux
getpgrp()函數 Unix/Linux
getpid()函數 Unix/Linux
getpmsg()函數 Unix/Linux
getppid()函數 Unix/Linux
getpriority()函數 Unix/Linux
getresuid()函數 Unix/Linux
getrlimit()函數 Unix/Linux
get_robust_list()函數 Unix/Linux
getrusage()函數 Unix/Linux
getsid()函數 Unix/Linux
getsockname()函數 Unix/Linux
getsockopt()函數 Unix/Linux
get_thread_area()函數 Unix/Linux
gettid()函數 Unix/Linux
gettimeofday()函數 Unix/Linux
getuid()函數 Unix/Linux
getunwind()函數 Unix/Linux
gtty()函數 Unix/Linux
idle()函數 Unix/Linux
outb()函數 Unix/Linux
inb_p()函數 Unix/Linux
inl()函數 Unix/Linux
inl_p()函數 Unix/Linux
inotify_add_watch()函數 Unix/Linux
inotify_init()函數 Unix/Linux
inotify_rm_watch()函數 Unix/Linux
outb()函數 Unix/Linux
insl()函數 Unix/Linux
insw()函數 Unix/Linux
intro()函數 Unix/Linux
inw()函數 Unix/Linux
inw_p()函數 Unix/Linux
io_cancel()函數 Unix/Linux
ioctl()函數 Unix/Linux
ioctl_list()函數 Unix/Linux
io_destroy()函數 Unix/Linux
io_getevents()函數 Unix/Linux
ioperm()函數 Unix/Linux
iopl()函數 Unix/Linux
ioprio_set()函數 Unix/Linux
io_setup()函數 Unix/Linux
io_submit()函數 Unix/Linux
ipc()函數 Unix/Linux
isastream()函數 Unix/Linux
kexec_load()函數 Unix/Linux
keyctl()函數 Unix/Linux
kill()函數 Unix/Linux
killpg()函數 Unix/Linux
lchown()函數 Unix/Linux
linkat()函數 Unix/Linux
link()函數 Unix/Linux
listen()函數 Unix/Linux
_llseek()函數 Unix/Linux
llseek()函數 Unix/Linux
lock()函數 Unix/Linux
lookup_dcookie()函數 Unix/Linux
lseek()函數 Unix/Linux
lstat()函數 Unix/Linux
madvise()函數 Unix/Linux
mincore()函數 Unix/Linux
mkdirat()函數 Unix/Linux
mkdir()函數 Unix/Linux
mknod()函數 Unix/Linux
mlockall()函數 Unix/Linux
mlock()函數 Unix/Linux
mmap2()函數 Unix/Linux
mmap()函數 Unix/Linux
modify_ldt()函數 Unix/Linux
mount()函數 Unix/Linux
move_pages()函數 Unix/Linux
mprotect()函數 Unix/Linux
mpx()函數 Unix/Linux
mq_getsetattr()函數 Unix/Linux
mremap()函數 Unix/Linux
msgctl()函數 Unix/Linux
msgget()函數 Unix/Linux
msgop()函數 Unix/Linux
msgsnd()函數 Unix/Linux
msync()函數 Unix/Linux
multiplexer()函數 Unix/Linux
munlockall()函數 Unix/Linux
munlock()函數 Unix/Linux
munmap()函數 Unix/Linux
nanosleep()函數 Unix/Linux
_newselect()函數 Unix/Linux
nfsservctl()函數 Unix/Linux
nice()函數 Unix/Linux
obsolete()函數 Unix/Linux
oldfstat()函數 Unix/Linux
oldlstat()函數 Unix/Linux
oldolduname()函數 Unix/Linux
oldstat()函數 Unix/Linux
olduname()函數 Unix/Linux
openat()函數 Unix/Linux
open()函數 Unix/Linux
outb()函數 Unix/Linux
outb_p()函數 Unix/Linux
outsb()函數 Unix/Linux
outsl()函數 Unix/Linux
outsw()函數 Unix/Linux
outw()函數 Unix/Linux
outw_p()函數 Unix/Linux
path_resolution()函數 Unix/Linux
pause()函數 Unix/Linux
perfmonctl()函數 Unix/Linux
personality()函數 Unix/Linux
pipe()函數 Unix/Linux
pivot_root()函數 Unix/Linux
poll()函數 Unix/Linux
posix_fadvise()函數 Unix/Linux
ppoll()函數 Unix/Linux
prctl()函數 Unix/Linux
pread()函數 Unix/Linux
prof()函數 Unix/Linux
pselect()函數 Unix/Linux
ptrace()函數 Unix/Linux
putmsg()函數 Unix/Linux
putpmsg()函數 Unix/Linux
pwrite()函數 Unix/Linux
query_module()函數 Unix/Linux
quotactl()函數 Unix/Linux
readahead()函數 Unix/Linux
readdir()函數 Unix/Linux
read()函數 Unix/Linux
readlinkat()函數 Unix/Linux
readlink()函數 Unix/Linux
readv()函數 Unix/Linux
reboot()函數 Unix/Linux
recvfrom()函數 Unix/Linux
recv()函數 Unix/Linux
recvmsg()函數 Unix/Linux
remap_file_pages()函數 Unix/Linux
renameat()函數 Unix/Linux
rename()函數 Unix/Linux
request_key()函數 Unix/Linux
rmdir()函數 Unix/Linux
sbrk()函數 Unix/Linux
sched_setaffinity()函數 Unix/Linux
sched_getparam()函數 Unix/Linux
sched_get_priority_max()函數 Unix/Linux
sched_get_priority_min()函數 Unix/Linux
sched_setscheduler()函數 Unix/Linux
sched_rr_get_interval()函數 Unix/Linux
sched_setparam()函數 Unix/Linux
sched_yield()函數 Unix/Linux
security()函數 Unix/Linux
select()函數 Unix/Linux
select_tut()函數 Unix/Linux
semctl()函數 Unix/Linux

chmod()函數 Unix/Linux

名稱

chmod, fchmod - 更改文件的權限

內容簡介

#include

#include

int chmod(const char \*path, mode\_t mode); int fchmod(int fildes, mode\_t mode); 

描述

給定的文件路徑或引用fildes的的模式改變。

所指定的「或」以下模式:

標籤

描述

S_ISUID

04000 set user ID on execution

S_ISGID

02000 set group ID on execution

S_ISVTX

01000 sticky bit

S_IRUSR

00400 read by owner

S_IWUSR

00200 write by owner

S_IXUSR

00100 execute/search by owner

S_IRGRP

00040 read by group

S_IWGRP

00020 write by group

S_IXGRP

00010 execute/search by group

S_IROTH

00004 read by others

S_IWOTH

00002 write by others

S_IXOTH

00001 execute/search by others

The effective UID of the calling process must match the owner of the file, or the process must be privileged (Linux: it must have the CAP_FOWNER capability).

If the calling process is not privileged (Linux: does not have the CAP_FSETIDcapability), and the group of the file does not match the effective group ID of the process or one of its supplementary group IDs, the S_ISGID bit will be turned off, but this will not cause an error to be returned.

As a security measure, depending on the file system, the set-user-ID and set-group-ID execution bits may be turned off if a file is written. (On Linux this occurs if the writing process does not have the CAP_FSETID capability.) On some file systems, only the superuser can set the sticky bit, which may have a special meaning. For the sticky bit, and for set-user-ID and set-group-ID bits on directories, see stat(2).

On NFS file systems, restricting the permissions will immediately influence already open files, because the access control is done on the server, but open files are maintained by the client. Widening the permissions may be delayed for other clients if attribute caching is enabled on them.

返回值

On success, zero is returned. On error, -1 is returned, and errno is set appropriately.

錯誤

根據文件系統上的,其他錯誤,也可以返回,chmod() 更普遍的錯誤列舉如下:

Error Code

描述

EACCES

Search permission is denied on a component of the path prefix. (See also path_resolution(2).)

EFAULT

path points outside your accessible address space.

EIO

An I/O error occurred.

ELOOP

Too many symbolic links were encountered in resolving path.

ENAMETOOLONG

path is too long.

ENOENT

The file does not exist.

ENOMEM

Insufficient kernel memory was available.

ENOTDIR

A component of the path prefix is not a directory.

EPERM

The effective UID does not match the owner of the file, and the process is not privileged (Linux: it does not have theCAP_FOWNER capability).

EROFS

The named file resides on a read-only file system.

The general errors for fchmod() are listed below:

EBADF

The file descriptor fildes is not valid.

EIO

See above.

EPERM

See above.

EROFS

See above.

遵循於

4.4BSD, SVr4, POSIX.1-2001.

另請參閱

  • chown (2)

  • execve (2)

  • fchmodat (2)

  • open (2)

  • path_resolution (2)

  • stat (2)