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diff --git a/man2/mknod.2 b/man2/mknod.2 new file mode 100644 index 0000000..0925aea --- /dev/null +++ b/man2/mknod.2 @@ -0,0 +1,302 @@ +.\" This manpage is Copyright (C) 1992 Drew Eckhardt; +.\" and Copyright (C) 1993 Michael Haardt +.\" and Copyright (C) 1993,1994 Ian Jackson +.\" and Copyright (C) 2006, 2014, Michael Kerrisk +.\" +.\" SPDX-License-Identifier: GPL-1.0-or-later +.\" +.\" Modified 1996-08-18 by urs +.\" Modified 2003-04-23 by Michael Kerrisk +.\" Modified 2004-06-23 by Michael Kerrisk <mtk.manpages@gmail.com> +.\" +.TH mknod 2 2023-03-31 "Linux man-pages 6.05.01" +.SH NAME +mknod, mknodat \- create a special or ordinary file +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <sys/stat.h> +.PP +.BI "int mknod(const char *" pathname ", mode_t " mode ", dev_t " dev ); +.PP +.BR "#include <fcntl.h> " "/* Definition of AT_* constants */" +.B #include <sys/stat.h> +.PP +.BI "int mknodat(int " dirfd ", const char *" pathname ", mode_t " mode \ +", dev_t " dev ); +.fi +.PP +.RS -4 +Feature Test Macro Requirements for glibc (see +.BR feature_test_macros (7)): +.RE +.PP +.BR mknod (): +.nf + _XOPEN_SOURCE >= 500 +.\" || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED + || /* Since glibc 2.19: */ _DEFAULT_SOURCE + || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE +.fi +.SH DESCRIPTION +The system call +.BR mknod () +creates a filesystem node (file, device special file, or +named pipe) named +.IR pathname , +with attributes specified by +.I mode +and +.IR dev . +.PP +The +.I mode +argument specifies both the file mode to use and the type of node +to be created. +It should be a combination (using bitwise OR) of one of the file types +listed below and zero or more of the file mode bits listed in +.BR inode (7). +.PP +The file mode is modified by the process's +.I umask +in the usual way: in the absence of a default ACL, the permissions of the +created node are +.RI ( mode " & \[ti]" umask ). +.PP +The file type must be one of +.BR S_IFREG , +.BR S_IFCHR , +.BR S_IFBLK , +.BR S_IFIFO , +or +.B S_IFSOCK +.\" (S_IFSOCK since Linux 1.2.4) +to specify a regular file (which will be created empty), character +special file, block special file, FIFO (named pipe), or UNIX domain socket, +respectively. +(Zero file type is equivalent to type +.BR S_IFREG .) +.PP +If the file type is +.B S_IFCHR +or +.BR S_IFBLK , +then +.I dev +specifies the major and minor numbers of the newly created device +special file +.RB ( makedev (3) +may be useful to build the value for +.IR dev ); +otherwise it is ignored. +.PP +If +.I pathname +already exists, or is a symbolic link, this call fails with an +.B EEXIST +error. +.PP +The newly created node will be owned by the effective user ID of the +process. +If the directory containing the node has the set-group-ID +bit set, or if the filesystem is mounted with BSD group semantics, the +new node will inherit the group ownership from its parent directory; +otherwise it will be owned by the effective group ID of the process. +.\" +.\" +.SS mknodat() +The +.BR mknodat () +system call operates in exactly the same way as +.BR mknod (), +except for the differences described here. +.PP +If the pathname given in +.I pathname +is relative, then it is interpreted relative to the directory +referred to by the file descriptor +.I dirfd +(rather than relative to the current working directory of +the calling process, as is done by +.BR mknod () +for a relative pathname). +.PP +If +.I pathname +is relative and +.I dirfd +is the special value +.BR AT_FDCWD , +then +.I pathname +is interpreted relative to the current working +directory of the calling process (like +.BR mknod ()). +.PP +If +.I pathname +is absolute, then +.I dirfd +is ignored. +.PP +See +.BR openat (2) +for an explanation of the need for +.BR mknodat (). +.SH RETURN VALUE +.BR mknod () +and +.BR mknodat () +return zero on success. +On error, \-1 is returned and +.I errno +is set to indicate the error. +.SH ERRORS +.TP +.B EACCES +The parent directory does not allow write permission to the process, +or one of the directories in the path prefix of +.I pathname +did not allow search permission. +(See also +.BR path_resolution (7).) +.TP +.B EBADF +.RB ( mknodat ()) +.I pathname +is relative but +.I dirfd +is neither +.B AT_FDCWD +nor a valid file descriptor. +.TP +.B EDQUOT +The user's quota of disk blocks or inodes on the filesystem has been +exhausted. +.TP +.B EEXIST +.I pathname +already exists. +This includes the case where +.I pathname +is a symbolic link, dangling or not. +.TP +.B EFAULT +.IR pathname " points outside your accessible address space." +.TP +.B EINVAL +.I mode +requested creation of something other than a regular file, device +special file, FIFO or socket. +.TP +.B ELOOP +Too many symbolic links were encountered in resolving +.IR pathname . +.TP +.B ENAMETOOLONG +.IR pathname " was too long." +.TP +.B ENOENT +A directory component in +.I pathname +does not exist or is a dangling symbolic link. +.TP +.B ENOMEM +Insufficient kernel memory was available. +.TP +.B ENOSPC +The device containing +.I pathname +has no room for the new node. +.TP +.B ENOTDIR +A component used as a directory in +.I pathname +is not, in fact, a directory. +.TP +.B ENOTDIR +.RB ( mknodat ()) +.I pathname +is relative and +.I dirfd +is a file descriptor referring to a file other than a directory. +.TP +.B EPERM +.I mode +requested creation of something other than a regular file, +FIFO (named pipe), or UNIX domain socket, and the caller +is not privileged (Linux: does not have the +.B CAP_MKNOD +capability); +.\" For UNIX domain sockets and regular files, EPERM is returned only in +.\" Linux 2.2 and earlier; in Linux 2.4 and later, unprivileged can +.\" use mknod() to make these files. +also returned if the filesystem containing +.I pathname +does not support the type of node requested. +.TP +.B EROFS +.I pathname +refers to a file on a read-only filesystem. +.SH VERSIONS +POSIX.1-2001 says: "The only portable use of +.BR mknod () +is to create a FIFO-special file. +If +.I mode +is not +.B S_IFIFO +or +.I dev +is not 0, the behavior of +.BR mknod () +is unspecified." +However, nowadays one should never use +.BR mknod () +for this purpose; one should use +.BR mkfifo (3), +a function especially defined for this purpose. +.PP +Under Linux, +.BR mknod () +cannot be used to create directories. +One should make directories with +.BR mkdir (2). +.\" and one should make UNIX domain sockets with socket(2) and bind(2). +.SH STANDARDS +POSIX.1-2008. +.SH HISTORY +.TP +.BR mknod () +SVr4, 4.4BSD, POSIX.1-2001 (but see VERSIONS). +.\" The Linux version differs from the SVr4 version in that it +.\" does not require root permission to create pipes, also in that no +.\" EMULTIHOP, ENOLINK, or EINTR error is documented. +.TP +.BR mknodat () +Linux 2.6.16, +glibc 2.4. +POSIX.1-2008. +.SH NOTES +There are many infelicities in the protocol underlying NFS. +Some of these affect +.BR mknod () +and +.BR mknodat (). +.SH SEE ALSO +.BR mknod (1), +.BR chmod (2), +.BR chown (2), +.BR fcntl (2), +.BR mkdir (2), +.BR mount (2), +.BR socket (2), +.BR stat (2), +.BR umask (2), +.BR unlink (2), +.BR makedev (3), +.BR mkfifo (3), +.BR acl (5), +.BR path_resolution (7) |