Linux man Command

>> man clear

NAME
       clear - clear the terminal screen

SYNOPSIS
       clear [-Ttype] [-V] [-x]

DESCRIPTION
       clear clears your screen if this is possible, including its scrollback buffer (if the extended “E3” capability
       is defined).  clear looks in the environment for the terminal type given by the environment variable TERM, and
       then in the terminfo database to determine how to clear the screen.

       clear  writes  to  the  standard output.  You can redirect the standard output to a file (which prevents clear
       from actually clearing the screen), and later cat the file to the screen, clearing it at that point.

OPTIONS
       -T type
            indicates the type of terminal.  Normally this option is unnecessary, because the default is  taken  from
            the  environment variable TERM.  If -T is specified, then the shell variables LINES and COLUMNS will also
            be ignored.

       -V   reports the version of ncurses which was used in this program, and exits.  The options are as follows:

       -x   do not attempt to clear the terminal's scrollback buffer using the extended “E3” capability.

>> man man

Output:

NAME
       man - an interface to the system reference manuals

SYNOPSIS
       man [man options] [[section] page ...] ...
       man -k [apropos options] regexp ...
       man -K [man options] [section] term ...
       man -f [whatis options] page ...
       man -l [man options] file ...
       man -w|-W [man options] page ...

DESCRIPTION
       man  is the system's manual pager.  Each page argument given to man is normally the name of a program, utility
       or function.  The manual page associated with each of these arguments is then found and displayed.  A section,
       if  provided,  will direct man to look only in that section of the manual.  The default action is to search in
       all of the available sections following a pre-defined order (see DEFAULTS), and to show only  the  first  page
       found, even if page exists in several sections.

       The table below shows the section numbers of the manual followed by the types of pages they contain.

       1   Executable programs or shell commands
       2   System calls (functions provided by the kernel)
       3   Library calls (functions within program libraries)
       4   Special files (usually found in /dev)
       5   File formats and conventions, e.g. /etc/passwd
       6   Games
       7   Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7)
       8   System administration commands (usually only for root)
       9   Kernel routines [Non standard]

       A manual page consists of several sections.

       Conventional  section  names  include  NAME,  SYNOPSIS,  CONFIGURATION, DESCRIPTION, OPTIONS, EXIT STATUS, RE‐
       TURN VALUE, ERRORS, ENVIRONMENT, FILES, VERSIONS, CONFORMING TO, NOTES, BUGS, EXAMPLE, AUTHORS, and SEE ALSO.

       The following conventions apply to the SYNOPSIS section and can be used as a guide in other sections.

       bold text          type exactly as shown.
       italic text        replace with appropriate argument.
       [-abc]             any or all arguments within [ ] are optional.
       -a|-b              options delimited by | cannot be used together.
       argument ...       argument is repeatable.
       [expression] ...   entire expression within [ ] is repeatable.

       Exact rendering may vary depending on the output device.  For instance, man will usually not be able to render
       italics when running in a terminal, and will typically use underlined or coloured text instead.

       The  command  or function illustration is a pattern that should match all possible invocations.  In some cases
       it is advisable to illustrate several exclusive invocations as is shown in the SYNOPSIS section of this manual
       page.

EXAMPLES
       man ls
           Display the manual page for the item (program) ls.

       man man.7
           Display  the manual page for macro package man from section 7.  (This is an alternative spelling of "man 7
           man".)

       man 'man(7)'
           Display the manual page for macro package man from section 7.  (This is another  alternative  spelling  of
           "man  7  man".  It may be more convenient when copying and pasting cross-references to manual pages.  Note
           that the parentheses must normally be quoted to protect them from the shell.)

       man -a intro
           Display, in succession, all of the available intro manual pages contained within the manual.  It is possi‐
           ble to quit between successive displays or skip any of them.

       man -t bash | lpr -Pps
           Format  the  manual  page for bash into the default troff or groff format and pipe it to the printer named
           ps.  The default output for groff is usually PostScript.  man --help should advise as to  which  processor
           is bound to the -t option.

       man -l -Tdvi ./foo.1x.gz > ./foo.1x.dvi
           This command will decompress and format the nroff source manual page ./foo.1x.gz into a device independent
           (dvi) file.  The redirection is necessary as the -T flag causes output to be directed to  stdout  with  no
           pager.   The output could be viewed with a program such as xdvi or further processed into PostScript using
           a program such as dvips.
       man -k printf
           Search the short descriptions and manual page names for the keyword printf as regular  expression.   Print
           out any matches.  Equivalent to apropos printf.

       man -f smail
           Lookup the manual pages referenced by smail and print out the short descriptions of any found.  Equivalent
           to whatis smail.