mknod function is the primitive for making special files,
such as files that correspond to devices. The GNU C Library includes
this function for compatibility with BSD.
The prototype for
mknod is declared in sys/stat.h.
mknodfunction makes a special file with name filename. The mode specifies the mode of the file, and may include the various special file bits, such as
S_IFCHR(for a character special file) or
S_IFBLK(for a block special file). See Testing File Type.
The dev argument specifies which device the special file refers to. Its exact interpretation depends on the kind of special file being created.
The return value is
0on success and
-1on error. In addition to the usual file name errors (see File Name Errors), the following
errnoerror conditions are defined for this function:
- The calling process is not privileged. Only the superuser can create special files.
- The directory or file system that would contain the new file is full and cannot be extended.
- The directory containing the new file can't be modified because it's on a read-only file system.
- There is already a file named filename. If you want to replace this file, you must remove the old file explicitly first.