introduction(9) Kernel Developer's Manual introduction(9)
NAME
introduction - HP-UX operating system and HP-UX Reference
INTRODUCTION
HP-UX is the Hewlett-Packard Company's implementation of a operating system that is compatible with various industry standards. It is
based on the System V Release 4 operating system (SVR4) and includes important features from the Fourth Berkeley Software Distribution(4BSD).
Improvements include enhanced capabilities and other features, developed by HP to make HP-UX a very powerful, useful, and reliable operat-
ing system, capable of supporting a wide range of applications ranging from simple text processing to sophisticated engineering graphics
and design. It can readily be used to control instruments and other peripheral devices. Real-time capabilities further expand the flexi-
bility of HP-UX as a powerful tool for solving tough problems in design, manufacturing, business, and other areas where responsiveness and
performance are important.
Extensive international language support enables HP-UX to interact with users in any of dozens of human languages. HP-UX interfaces easily
with local area networks and resource-sharing facilities. By using industry-standard protocols, HP-UX provides flexible interaction with
other computers and operating systems. Optional software products extend HP-UX capabilities into a broad range of specialized needs.
The is not a learning tool for beginners. It is primarily a reference tool that is most useful for experienced users of UNIX or UNIX-like
systems. If you are not already familiar with UNIX or HP-UX, refer to the series of Beginner's Guides, tutorial manuals, and other learn-
ing documents supplied with your system or available separately. System implementation and maintenance details are explained in the
OTHER MANPAGES
This introduction and the section intro manpages describe the "core" manpages that are delivered with HP-UX. Other manpages may be deliv-
ered separately with optional HP-UX and third-party software and may reside in the same directories as the core manpages, or in other
directories.
MANPAGE ORGANIZATION
The contents of the and its on-line counterpart are a number of independent entries called These are also called manual entries or refer-
ence pages.
For convenient reference, the manpages are divided into eight specialized sections. The printed manual also has a table of contents for
each volume and a composite index.
Each manpage consists of one or more printed pages, with the manpage name and section number printed in the upper corners. Manpages are
arranged alphabetically within each section of the reference, except for the intro page at the beginning of each section. Manpages are
referred to by name and section number, in the form pagename(section).
The manpages are available on-line through the command if the manpages are present on the system. Refer to the man(1) manpage in Section 1
for more information.
Each page in the printed manual has two page numbers, printed at the bottom of the page. The center page number starts over with page 1 at
the beginning of each new manpage; it is placed between two dashes in normal typeface. The number printed at the outside corner on each
page is the sequence number of the page within the volume. Users usually locate manpages by the alphabetic headings at the top of the page
as when reading a dictionary.
Some manpages describe two or more commands or routines. In such cases, the manpage is usually named for the first command or function
that appears in the NAME section. Occasionally, a manpage name appears as a group descriptor in the NAME section. In such instances, the
name describes the commands or functions in more general terms. For example, the acct(1M) manpage with group descriptor describes the and
other commands, while the string(3C) manpage with group descriptor describes many character string functions.
SECTIONS OF THE HP-UX REFERENCE
The contains the following sections:
Volume Table of Contents (Printed Volumes)
A complete listing of all manpages in the order they appear in each section, as well as alphabetically intermixed lists of all com-
mand, function, and feature names that are different from the manpage where they appear.
Section 1: User Commands
Programs that are usually invoked directly by users or from command language procedures (scripts).
Section 1M: System Administration Commands
Commands used for system installation and maintenance, including boot processes, crash recovery, system integrity testing, and other
needs. Most commands in this section require the superuser privilege.
Section 2: System Calls
Entries into the HP-UX kernel, including the C-language interface. These topics are primarily of interest to programmers.
Section 3: Library Functions
Available subroutines that reside (in binary form) in various system libraries. These topics are primarily of interest to program-
mers.
Section 4: File Formats
The structure of various types of files, such as header files, primarily of interest to administrators and programmers. For exam-
ple, the link editor output file format is described in a.out(4). Files that are used only by a single command (such as intermedi-
ate files used by assemblers) are not described. C-language declarations corresponding to the formats in Section 4 can be found in
the directories and
Section 5: Miscellaneous Topics
A variety of information, such as descriptions of character sets, macro packages, and kernel tunables.
Section 6 (Unused)
This section was traditionally used for games. None are shipped with HP-UX.
Section 7: Device Special Files
The characteristics of device special files (DSF) that provide the link between HP-UX and system I/O devices. The names for each
topic usually refer to the type of I/O device rather than to the names of individual special files.
Section 8: System Administration Commands
Some UNIX and Linux vendors put system administration commands here. Some third party vendors install commands in this section in
HP-UX.
Section 9: General Information
General introductions (such as this) and a glossary of terms used in the HP-UX environment.
This section is also used by the Driver Development Kit to store its function and structure manpages, using the section numbers 9E,
9F, and 9S.
Composite Index (Printed Manual)
An alphabetical listing of keywords and topics based on the NAME section near the beginning of each manpage as well as other infor-
mation, cross-referenced to manpage names and sections. The index also contains references to built-in features in the various com-
mand interpreters ("shells").
MANPAGE FORMATS
All manpages follow an established section heading format, but not all section headings are included in each manpage. A few manpages have
self-explanatory specialized headings.
NAME Gives the names of the commands, functions, or features and briefly states the purpose.
SYNOPSIS
Summarizes the syntax of the command or program entity. A few conventions are used:
characters indicate literal characters that should be entered exactly as they appear. These characters appear in bold in the online
manpages.
Italic strings represent variable elements that should be replaced with appropriate values.
Roman square brackets ([]) indicate that the contents are optional.
Roman braces ({}) indicate a required element, usually in a choice.
Ellipses (...) indicate that the previous element and its preceding whitespace (if any) can be repeated.
An argument beginning with a dash a plus sign or an equal sign is often defined as a command option, even if it appears in a posi-
tion where a file name could appear. Therefore, it is unwise to have files names that begin with or
Optional subsections can include the following:
Parameters For functions, a description of the parameters in the preceding syntax.
Structure Members
For structures, a description of the structure elements in the preceding syntax.
Remarks
Information about special software or hardware requirements.
DESCRIPTION
Discusses the function and behavior of each entry.
Optional subsections can include the following:
Options For commands, a description of the switch arguments.
Operands
For commands, a description of the nonswitch arguments and keywords.
Access Control Lists
Multithread Usage
Security Restrictions
Information on restrictions and privileges required to use the item.
EXTERNAL INFLUENCES
Information on what external factors, such as environment variables, may affect system behavior.
Optional subsections can include the following:
Environment Variables The effect of language-related and other environment variables on system behavior,
International Code Set Support
Whether there is support for single- and multibyte characters,
NETWORKING FEATURES
Information under this heading is applicable only if you are using the network feature described there.
Optional subsections can include the following:
NFS Information on the network file system.
RETURN VALUE
Describes the values returned by function calls or in the return code by commands.
DIAGNOSTICS
For commands, the diagnostic information that may be produced. Self-explanatory messages are not listed.
Optional subsections can include the following:
Errors
Warnings
ERRORS For functions, the function error values (set in and their corresponding error conditions.
EXAMPLES
Examples of typical usage.
WARNINGS
Potential problems and deficiencies.
DEPENDENCIES
Variations in HP-UX operation that are related to the use of specific hardware, software, or combinations of hardware and software.
AUTHOR Indicates the principal developer of the software documented by the manpage. Unless noted otherwise, the source of an entry is Sys-
tem V.
FILES The file names that are used or affected by the program or command.
SEE ALSO
Provides references to related manpages and other documentation.
STANDARDS CONFORMANCE
For each command or subroutine entry point addressed by one or more of the following industry standards, the standard specifications
to which that HP-UX component conforms.
The various standards are:
AES OSF Application Environment Specification
ANSI C ANSI X3.159-1989
FIPS 151-1 Federal Information Processing Standard 151-1 (National Institute of Standards and Technology)
FIPS 151-2 Federal Information Processing Standard 151-2 (National Institute of Standards and Technology)
POSIX.1 IEEE Standard 1003.1-1988 (IEEE Computer Society) (Portable Operating System Interface for Computer Environments)
POSIX.2 IEEE Standard 1003.2-1990 (IEEE Computer Society) (Portable Operating System Interface for Computer Environments)
POSIX.4 IEEE Standard 1003.1b-1993 (IEEE Computer Society) (Portable Operating System Interface for Computer Environments)
SVID2 System V Interface Definition Issue 2
SVID3 System V Interface Definition Issue 3
XPG2 X/Open Portability Guide Issue 2 (X/Open, Ltd.)
XPG3 X/Open Portability Guide Issue 3 (X/Open, Ltd.)
XPG4 X/Open Portability Guide Issue 4 (X/Open, Ltd.)
XPG4.2 X/Open Portability Guide Issue 4 Version 2 (X/Open, Ltd.)
GETTING STARTED WITH HP-UX
This is a very brief overview of how to use the HP-UX system: how to log in and log out, how to communicate through your machine, and how
to run a program.
HP-UX uses control characters to perform certain functions. Control characters are generally shown in the form such as for Control-D.
Hold down the (key while you press the character key.
The key names and refer to the same key.
Logging In
To log in you must have a valid user name and password, which can be obtained from your system administrator.
When a connection has been established, the system displays on your terminal. Type your user name and press the key. Enter your password
(it is not echoed by the system) and press
A list of copyright notices and a message-of-the-day may greet you before the first prompt.
It is important that you type your login name with lowercase letters, if possible. If you type uppercase letters, HP-UX assumes that your
terminal cannot generate lowercase letters, and treats subsequent uppercase input as lowercase.
When you log in successfully, the system starts your login shell. The default is the POSIX shell, The POSIX shell (and its predecessors,
the Korn and Bourne shells) use as the default prompt for users. The C shell uses All the shells use as the default superuser prompt.
See login(1) for more on login, passwd(1) to change your password, chsh(1) to change your login shell.
Logging Out
You can log out of the shells by typing an command or the (end-of-file) character (see the subsection below). The shell terminates and the
prompt appears again. (If you are using the C, Korn, or POSIX shells, respectively, see csh(1), ksh(1), or sh-posix(1) for information
about the special command.)
How to Communicate Through Your Terminal
HP-UX gathers keyboard input characters and saves them in a buffer. The accumulated characters are not passed to the shell or other pro-
gram until you type
HP-UX terminal input/output is full-duplex. It has full read-ahead, which means that you can type at any time, even while a program is
printing on your display or terminal. Of course, if you type during output, the output display will have the input characters interspersed
in it. However, whatever you type will be saved and interpreted in the correct sequence. There is a limit to the amount of read-ahead,
but it is generous and not likely to be exceeded unless the system is severely overloaded or operating abnormally. When the read-ahead
limit is exceeded, the system throws away the saved characters.
The stty(1) manpage tells you how to describe the characteristics of your terminal to the system. The profile(4) manpage explains how to
accomplish this task automatically every time you log in.
Special Interactive Characters
A number of special characters are used to control the input and output of your terminal. These characters have defaults and can be rede-
fined with the command (see stty(1)). Definitions of the names are in termio(7) and termiox(7).
The system administrator can modify the system login defaults by changing the characteristics of the device file with the command.
---------------------------------------------------------------
stty System Default At Login Common User
Name Character (ASCII Name; Key Names) Redefinition
---------------------------------------------------------------
eof ^D (EOT)
erase # ^H (BS; Backspace)
kill @ ^U (NAK), ^X (CAN)
intr ^? (DEL; Delete, Rub, Rubout) ^C (ETX)
quit ^ (FS)
start ^Q (DC1; X-ON)
stop ^S (DC3; X-OFF)
---------------------------------------------------------------
The character terminates "file" input from the terminal, as read by programs and scripts. By extension, can also terminate the shell (see
the subsection above).
The character erases the last character typed. Successive uses of will erase characters back to, but not beyond, the beginning of the
input line.
The character deletes all characters typed before it on a terminal input line.
The character generates an interrupt signal that bypasses the input buffer. This signal generally causes whatever program you are running
to terminate. It can be used to stop a long printout that you don't want. However, programs can arrange either to ignore this signal
altogether, or to be notified when it happens (instead of being terminated). For example, the editor catches interrupts and stops what it
is doing, instead of terminating, so that an interrupt can be used to halt an editing operation without losing the file being edited.
The character generates a quit signal that bypasses the input buffer and most program traps and causes a running program to terminate. It
can cause a core dump in the current directory.
The character can be used to pause output to the terminal. It is commonly used on video terminals to suspend output to the display while
you read what is already being displayed. You can then resume output by typing the character. When and are used to suspend or resume out-
put, they bypass the keyboard command-line buffer and are not passed to the program. However, any other characters typed on the keyboard
are saved and used as input later in the program.
The and characters can be used as normal text characters if you escape them with a preceding as in Therefore, to erase a you need two
The and characters cannot be escaped on the input line.
End-of-Line and Tab Characters
Besides adapting to the speed of the terminal, HP-UX tries to be intelligent as to whether you have a terminal with a newline (line-feed)
key, or whether it must be simulated with a return/line-feed character pair. In the latter case, all incoming return characters are
changed to line-feed characters (the standard line delimiter), and a return/line-feed pair is echoed to the terminal. If you get into the
wrong mode, use the command to correct it (see stty(1)).
Tab characters are used freely in HP-UX source programs. If your terminal does not have the tab function, you can arrange to have tab
characters changed into spaces during output, and echoed as spaces during input. The command sets or resets this mode. By default, the
system assumes that tabs are set every eight character positions. The command (see tabs(1)) can set tab stops on your terminal, if the
terminal supports tabs.
How to Run a Program
When you have successfully logged into HP-UX, the shell monitors input from your terminal. The shell accepts typed lines from the termi-
nal, splits them into command names and arguments, then executes the command. The command can be the name of a shell built-in, an exe-
cutable script of commands, or an executable program. There is nothing special about system-provided commands, except that they are kept
in directories where the shell can find them. You can also keep commands in your own directories and arrange for the shell to find them
there.
The command name is the first word on an input line to the shell; the command and its arguments are separated from one another by blanks
(one or more space and/or tab characters).
When a program terminates, the shell ordinarily regains control and prompts you to indicate that it is ready for another command. The
shell has many other capabilities, which are described in detail in the appropriate manpages: sh-posix(1) for the POSIX shell, ksh(1) for
the Korn shell, or csh(1) for the C shell.
The Current Directory
HP-UX has a file system arranged in a hierarchy of directories. When the system administrator gave you a user name, he or she also created
a directory for you (ordinarily with the same name as your user name, and known as your or directory). When you log in, that directory
becomes your or directory, and any file name you type is assumed to be in that directory by default. Because you are the owner of this
directory, you have full permission to read, write, alter, or destroy its contents. The permissions you have for other directories and
files will have been granted or denied to you by their respective owners, or by the system administrator. To change the current working
directory use the command (see cd(1)).
Path Names
To refer to files not in the current directory, you must use a path name. Full (absolute) path names begin with which is the name of the
directory of the whole file system. After the slash comes the name of each directory containing the next subdirectory (followed by a until
finally the file name is reached (for example, refers to file in directory while is itself a subdirectory of is a subdirectory of the root
directory). See glossary(9) for a formal definition of
If your current directory contains subdirectories, the path names of files in them begin with the name of the corresponding subdirectory
(without a prefixed Generally, a path name can be used anywhere a file name is required.
Important commands that modify the contents of directories are and which respectively copy, move (that is, rename, relocate, or both), and
remove files. To determine the status of files or the contents of directories, use the command. Use to make directories, to destroy them,
and to rename them. See cp(1), ls(1), mkdir(1), mv(1), rm(1), and rmdir(1).
Writing a Program
To enter the text of a source program into an HP-UX file, use a text editing program such as or (see vi(1), ex(1), and ed(1)). The three
principal languages available under HP-UX are C (see cc_bundled(1) and cc(1)), FORTRAN (see f77(1)), and aC++ (see aCC(1)). After the pro-
gram text has been entered with the editor and written into a file (whose name has the appropriate suffix), you can give the name of that
file to the appropriate language processor as an argument. Normally, the output of the language processor will be left in a file named in
the current directory. Since the results of a subsequent compilation may also be placed in thus overwriting the current output, you may
want to use to give the output a unique name. If the program is written in assembly language, you will probably need to link library sub-
routines with it (see ld(1)). FORTRAN, C, and aC++ call the linker automatically.
When you have gone through this entire process without encountering any diagnostics, the resulting program can be run by giving its name to
the shell in response to the prompt.
Your programs can receive arguments from the command line just as system programs do by using the argc and argv parameters. For more
information, see your language's
Text Processing
Almost all text is entered through a text editor. The editor preferred above all others provided with HP-UX is the editor. For batch-pro-
cessing text files, the editor is very efficient. The editor is useful for handling certain situations while using but most other editors
are rarely used except in various scripts.
The following editors are the same program masquerading under various names: and (see vi(1)) and and (see ex(1)). For information about
the stream editor, see sed(1). The line editor is described in ed(1).
The commands most often used to display text on a terminal are and See cat(1), more(1), and pr(1). The command simply copies ASCII text to
the terminal, with no processing at all. The command displays text on the terminal a screenful at a time, pausing for an acknowledgement
from the user before continuing. The command paginates text, supplies headings, and has a facility for multicolumn output. is most com-
monly used in conjunction with the command (see lp(1)) to pipe formatted text to a line printer.
Interuser Communication
Certain commands provide interuser communication. Even if you do not plan to use them, it could be beneficial to learn about them, because
someone else may direct them toward you. To communicate with another user that is currently logged in, you can use to transfer text
directly to that user's terminal display (if permission to do so has been granted by the other user). Otherwise, or (in order of ease of
use) can send a message to another user's mailbox. The user is then informed by HP-UX that mail has arrived (if currently logged in) or
mail is present (when the user next logs in). Refer to elm(1), mail(1), mailx(1), and write(1) for explanations of how these commands are
used.
ACKNOWLEDGEMENTS
UNIX is a registered trademark of The Open Group.
SEE ALSO
cat(1), cc_bundled(1), cd(1), chsh(1), cp(1), csh(1), ed(1), ex(1), ksh(1), ld(1), login(1), lp(1), ls(1), mail(1), mailx(1), man(1),
mkdir(1), more(1), mv(1), passwd(1), pr(1), rm(1), rmdir(1), sed(1), sh(1), sh-posix(1), stty(1), tabs(1), vi(1), write(1), a.out(4), pro-
file(4), glossary(9).
The HP Technical Documentation website at:
introduction(9)