diff options
Diffstat (limited to 'man3p/mknod.3p')
| -rw-r--r-- | man3p/mknod.3p | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/man3p/mknod.3p b/man3p/mknod.3p new file mode 100644 index 000000000..ac58c9518 --- /dev/null +++ b/man3p/mknod.3p @@ -0,0 +1,207 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "MKNOD" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" mknod +.SH NAME +mknod \- make a directory, a special file, or a regular file +.SH SYNOPSIS +.LP +\fB#include <sys/stat.h> +.br +.sp +int mknod(const char *\fP\fIpath\fP\fB, mode_t\fP \fImode\fP\fB, dev_t\fP +\fIdev\fP\fB); \fP +\fB +.br +\fP +.SH DESCRIPTION +.LP +The \fImknod\fP() function shall create a new file named by the pathname +to which the argument \fIpath\fP points. +.LP +The file type for \fIpath\fP is OR'ed into the \fImode\fP argument, +and the application shall select one of the following +symbolic constants: +.TS C +center; l l. +\fBName\fP \fBDescription\fP +S_IFIFO FIFO-special +S_IFCHR Character-special (non-portable) +S_IFDIR Directory (non-portable) +S_IFBLK Block-special (non-portable) +S_IFREG Regular (non-portable) +.TE +.LP +The only portable use of \fImknod\fP() is to create a FIFO-special +file. If \fImode\fP is not S_IFIFO or \fIdev\fP is not 0, +the behavior of \fImknod\fP() is unspecified. +.LP +The permissions for the new file are OR'ed into the \fImode\fP argument, +and may be selected from any combination of the +following symbolic constants: +.TS C +center; l2 l. +\fBName\fP \fBDescription\fP +S_ISUID Set user ID on execution. +S_ISGID Set group ID on execution. +S_IRWXU Read, write, or execute (search) by owner. +S_IRUSR Read by owner. +S_IWUSR Write by owner. +S_IXUSR Execute (search) by owner. +S_IRWXG Read, write, or execute (search) by group. +S_IRGRP Read by group. +S_IWGRP Write by group. +S_IXGRP Execute (search) by group. +S_IRWXO Read, write, or execute (search) by others. +S_IROTH Read by others. +S_IWOTH Write by others. +S_IXOTH Execute (search) by others. +S_ISVTX On directories, restricted deletion flag. +.TE +.LP +The user ID of the file shall be initialized to the effective user +ID of the process. The group ID of the file shall be +initialized to either the effective group ID of the process or the +group ID of the parent directory. Implementations shall provide +a way to initialize the file's group ID to the group ID of the parent +directory. Implementations may, but need not, provide an +implementation-defined way to initialize the file's group ID to the +effective group ID of the calling process. The owner, group, +and other permission bits of \fImode\fP shall be modified by the file +mode creation mask of the process. The \fImknod\fP() +function shall clear each bit whose corresponding bit in the file +mode creation mask of the process is set. +.LP +If \fIpath\fP names a symbolic link, \fImknod\fP() shall fail and +set \fIerrno\fP to [EEXIST]. +.LP +Upon successful completion, \fImknod\fP() shall mark for update the +\fIst_atime\fP, \fIst_ctime\fP, and \fIst_mtime\fP +fields of the file. Also, the \fIst_ctime\fP and \fIst_mtime\fP fields +of the directory that contains the new entry shall be +marked for update. +.LP +Only a process with appropriate privileges may invoke \fImknod\fP() +for file types other than FIFO-special. +.SH RETURN VALUE +.LP +Upon successful completion, \fImknod\fP() shall return 0. Otherwise, +it shall return -1, the new file shall not be created, and +\fIerrno\fP shall be set to indicate the error. +.SH ERRORS +.LP +The \fImknod\fP() function shall fail if: +.TP 7 +.B EACCES +A component of the path prefix denies search permission, or write +permission is denied on the parent directory. +.TP 7 +.B EEXIST +The named file exists. +.TP 7 +.B EINVAL +An invalid argument exists. +.TP 7 +.B EIO +An I/O error occurred while accessing the file system. +.TP 7 +.B ELOOP +A loop exists in symbolic links encountered during resolution of the +\fIpath\fP argument. +.TP 7 +.B ENAMETOOLONG +The length of a pathname exceeds {PATH_MAX} or a pathname component +is longer than {NAME_MAX}. +.TP 7 +.B ENOENT +A component of the path prefix specified by \fIpath\fP does not name +an existing directory or \fIpath\fP is an empty +string. +.TP 7 +.B ENOSPC +The directory that would contain the new file cannot be extended or +the file system is out of file allocation resources. +.TP 7 +.B ENOTDIR +A component of the path prefix is not a directory. +.TP 7 +.B EPERM +The invoking process does not have appropriate privileges and the +file type is not FIFO-special. +.TP 7 +.B EROFS +The directory in which the file is to be created is located on a read-only +file system. +.sp +.LP +The \fImknod\fP() function may fail if: +.TP 7 +.B ELOOP +More than {SYMLOOP_MAX} symbolic links were encountered during resolution +of the \fIpath\fP argument. +.TP 7 +.B ENAMETOOLONG +Pathname resolution of a symbolic link produced an intermediate result +whose length exceeds {PATH_MAX}. +.sp +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.SS Creating a FIFO Special File +.LP +The following example shows how to create a FIFO special file named +\fB/home/cnd/mod_done\fP, with read/write permissions for +owner, and with read permissions for group and others. +.sp +.RS +.nf + +\fB#include <sys/types.h> +#include <sys/stat.h> +.sp + +dev_t dev; +int status; +\&... +status = mknod("/home/cnd/mod_done", S_IFIFO | S_IWUSR | + S_IRUSR | S_IRGRP | S_IROTH, dev); +\fP +.fi +.RE +.SH APPLICATION USAGE +.LP +The \fImkfifo\fP() function is preferred over this function for making +FIFO special +files. +.SH RATIONALE +.LP +The POSIX.1-1990 standard required that the group ID of a newly created +file be set to the group ID of its parent directory or +to the effective group ID of the creating process. FIPS 151-2 required +that implementations provide a way to have the group ID be +set to the group ID of the containing directory, but did not prohibit +implementations also supporting a way to set the group ID to +the effective group ID of the creating process. Conforming applications +should not assume which group ID will be used. If it +matters, an application can use \fIchown\fP() to set the group ID +after the file is created, +or determine under what conditions the implementation will set the +desired group ID. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fIchmod\fP() , \fIcreat\fP() , \fIexec\fP() , \fImkdir\fP() , \fImkfifo\fP() +, +\fIopen\fP() , \fIstat\fP() , \fIumask\fP() , the Base +Definitions volume of IEEE\ Std\ 1003.1-2001, \fI<sys/stat.h>\fP +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . |