3. Getting Help While on the System

Finding Out What's Available

All commands on the UNIX system are described online in a collection of files called as ``man pages'', because they were originally pages from the UNIX Programmer's Manual.

The full set of man pages is organized into many sections having titles such as: 

          commands           games
          library routines   system maintenance
          special files      device drivers
          file formats       system calls
          miscellaneous
On most UNIX systems, you can find out what the categories are by typing: 
     apropos intro
If you know the name of a command, you can view its man page at your terminal. If you don't know its name, you can use the apropos command, which searches through the header lines of the man pages for whatever keyword you supply and shows you a list of the man pages it finds. To use it, type 
     apropos topic
where topic is a word describing what you want to know. For example, if you can't remember the commands to run Fortran or use its libraries, you might type 
     apropos fortran
which would produce a list of man pages that contain ``fortran'' in their header lines: 

imsl              imsl (7)            - Fortran Subroutine Libraries for Numerical Computation
asa               asa (1)             - convert FORTRAN carriage-control output to printable form
asa               asa (1)             - convert FORTRAN carriage-control output to printable form
f77               f77 (1)             - FORTRAN compiler
f77_floatingpoint f77_floatingpoint (3f) - FORTRAN IEEE floating-point definitions
fpr               fpr (1)             - convert FORTRAN carriage-control output to printable form
fputc             putc (3f)           - write a character to a FORTRAN logical unit
fsplit            fsplit (1)          - split a multi-routine FORTRAN file into individual files
intro             intro (1)           - introduction to FORTRAN Manual Pages
intro             intro (3f)          - introduction to FORTRAN library functions and subroutines
libm_double       libm_double (3f)    - FORTRAN access to double precision libm functions and subroutines
libm_quadruple    libm_quadruple (3f) - FORTRAN access to quadruple-precision libm functions (SPARC only)
libm_single       libm_single (3f)    - FORTRAN access to single-precision libm functions and subroutines
putc              putc (3f)           - write a character to a FORTRAN logical unit
ratfor            ratfor (1)          - rational FORTRAN dialect
tclose            topen (3f)          - FORTRAN tape I/O
topen             topen (3f)          - FORTRAN tape I/O
tread             topen (3f)          - FORTRAN tape I/O
trewin            topen (3f)          - FORTRAN tape I/O
tskipf            topen (3f)          - FORTRAN tape I/O
tstate            topen (3f)          - FORTRAN tape I/O
twrite            topen (3f)          - FORTRAN tape I/O
Notice that apropos does not require an exact case match: it successfully found uppercase FORTRAN and mixed-case Fortran. It will also find partial words, such as ``fortr''. The numbers in parentheses identify the section number for each man page. From this list you could choose the one you need.

Getting Specific Information

Once you know the names of the man pages you need, display them on the screen by giving the man command: 
     man [section] name  (on Solaris systems, man [-s section] name)
If you omit the section number, the man program searches through each section in turn until it finds the named man page. This is fine if name is unique. But a name may exist in more than one section, in which case omitting the section number would get you only the first man page.

Most manual sections have an ``intro'' man page, describing that section in general. So to find out more about library functions (section 3 of the man pages), type 

     man 3 intro    (on Solaris systems, man -s 3 intro)
When man displays information on your terminal, it pauses after each screenful, allowing you to read the current screenful before you go to the next. To see the next screenful, press the space bar. To see just one more line, press Return. To quit reading, type q.

World Wide Web

In general, UNIX man pages are not written with the novice in mind, and you may not find the answer to your question by using only apropos and man. Fortunately, other tools exist for finding information online. The Web is a useful source of online information, not only about UNIX, but about a wealth of topics, from sources all over the world. Using your Web browser, connect to the Hardlink's support page at 
     http://www.hardlink.net/support.html
From there, you have access to various forms of documentation, FAQs, and system resources.

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