HP-UX Reference (11i v3 07/02) - 7 Device (Special) Files, 9 General Information, Index (vol 10)

s
glossary(9) glossary(9)
special file
A file associated with an I/O device. Often called a device file. Special files are read and written the same
as ordinary files, but requests to read or write result in activation of the associated device. Due to con-
vention and consistency, these files should always reside in the
/dev directory. See also file.
special system processes
Special system processes are those which are critical to basic system operation. They include: the
scheduler, the initialization process (also known as init) and the pager.
SS/80
See CS/80.
standard error
The destination of error and special messages from a program, intended to be used for diagnostic messages.
The standard error output is often called stderr, and is automatically opened for writing on file descriptor
2 for every command invoked. By default, the user’s terminal is the destination of all data written to stan-
dard error, but it can be redirected elsewhere. Unlike standard input and standard output, which are
never used for data transfer in the "wrong" direction, standard error is occasionally read. This is not
recommended practice, since I/O redirection is likely to break a program doing this.
standard input
The source of input data for a program. The standard input file is often called stdin, and is automatically
opened for reading on file descriptor 0 for every command invoked. By default, the user’s terminal is the
source of all data read from standard input, but it can be redirected from another source.
standard output
The destination of output data from a program. The standard output file is often called stdout, and is
automatically opened for writing on file descriptor 1 for every command invoked. By default, the user’s ter-
minal is the destination of all data written to standard output, but it can be redirected elsewhere.
stderr
See standard error.
stdin
See standard input.
stdout
See standard output.
stream
A term most often used in conjunction with the standard I/O library routines documented in Section 3 of
this manual. A stream is simply a file pointer (declared as
FILE *stream) returned by the fopen(3S)
library routines. It may or may not have buffering associated with it (by default, buffering is assigned, but
this can be modified with setbuf(3S)).
sticky bit
A single bit in the mode of every file in the file system. The sticky bit has no significance if it is set on a
regular file.
If set on a directory, the files in that directory can be removed or renamed only by the owner of the file, the
owner of the directory containing the file, or superuser. See also chmod(2), rename(2), rmdir(2), and
unlink(2).
subdirectory
A directory that is one or more levels lower in the file system hierarchy than a given directory. Sometimes
called a subordinate directory.
subordinate directory
See subdirectory.
Subset 1980
See CS/80.
268 Hewlett-Packard Company − 23 − HP-UX 11i Version 3: February 2007