xref: /freebsd/contrib/less/README (revision 2235c7feac959bcc9ddfd6a2bc6be32102b1f84c)

**************************************************************************
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**                                                                      **
** The FreeBSD Project has chosen to redistribute and modify Less under **
** the 'Less License' (as described in the 'LICENSE' file).             **
**                                                                      **
**************************************************************************
**************************************************************************

                            Less, version 581

    This is the distribution of less, version 581, released 06 Apr 2021.
    This program is part of the GNU project (http://www.gnu.org).

    This program is free software.  You may redistribute it and/or
    modify it under the terms of either:

    1. The GNU General Public License, as published by the Free
       Software Foundation; either version 3, or (at your option) any
       later version.  A copy of this license is in the file COPYING.
    or
    2. The Less License, in the file LICENSE.

    Please report any problems at https://github.com/gwsw/less/issues.
    See https://greenwoodsoftware.com/less for the latest info.
    Source repository is at https://github.com/gwsw/less.git.

=========================================================================

The formatted manual page is in less.man.
The manual page nroff source is in less.nro.
Major changes made since the last posted version are in NEWS.

=======================================================================
INSTALLATION (Unix & Linux systems only):

1. Move the distributed source to its own directory and unpack it,
   if you have not already done so.

2. If you are building from a clone of a git repository,
   type "make -f Makefile.aut".
   If you are building from a numbered release package (a tar or
   zip file with a name like less-999.tar.gz or less-999.zip downloaded
   from greenwoodsoftware.com, not from github), you should skip this step.

3. Type "sh configure".
   This will generate a Makefile and a defines.h.
   Warning: if you have a GNU sed, make sure it is version 2.05 or later.

   The file INSTALL describes the usage of the configure program in
   general.  In addition, these options to configure are supported:

   --with-editor=program
     Specifies the default editor program used by the "v" command.
     The default is "vi".

   --with-regex=lib
     Specifies the regular expression library used by less for pattern
     matching.  The default is "auto", which means the configure program
     finds a regular expression library automatically.  Other values are:
        gnu            Use the GNU regex library.
        pcre           Use the PCRE library.
        pcre2          Use the PCRE2 library.
        posix          Use the POSIX-compatible regcomp.
        regcmp         Use the regcmp library.
        re_comp        Use the re_comp library.
        regcomp        Use the V8-compatible regcomp.
        regcomp-local  Use Henry Spencer's V8-compatible regcomp
                       (source is supplied with less).
        none           No regular expressions, only simple string matching.

   --with-secure
     Builds a "secure" version of less, with some features disabled
     to prevent users from viewing other files, accessing shell
     commands, etc.


4. It is a good idea to look over the generated Makefile and defines.h
   and make sure they look ok.  If you know of any peculiarities of
   your system that configure might not have detected, you may fix the
   Makefile now.  Take particular notice of the list of "terminal"
   libraries in the LIBS definition in the Makefile; these may need
   to be edited.  The terminal libraries will be some subset of
       -lncurses  -lcurses  -ltermcap  -ltermlib

   If you wish, you may edit defines.h to remove some optional features.
   If you choose not to include some features in your version, you may
   wish to edit the manual page "less.nro" and the help page "less.hlp"
   to remove the descriptions of the features which you are removing.
   If you edit less.hlp, you should run "make -f Makefile.aut help.c".

5. Type "make" and watch the fun.

6. If the make succeeds, it will generate the programs "less",
   "lesskey" and "lessecho" in your current directory.  Test the
   generated programs.

7. When satisfied that it works, if you wish to install it
   in a public place, type "make install".

   The default install destinations are:
        Executables (less, lesskey, lessecho) in /usr/local/bin
        Documentation (less.nro, lesskey.nro) in /usr/local/man/man1
   If you want to install any of these files elsewhere, define
   bindir and/or mandir to the appropriate directories.


Note to hackers: comments noting possible improvements are enclosed
in double curly brackets {{ like this }}.

(Note that the above note was originally written at a time when
"hackers" most commonly meant "enthusiastic and dedicated computer
programmers", not "persons who attempt to circumvent computer security".)



=======================================================================
INSTALLATION (MS-DOS systems only,
              with Microsoft C, Borland C, or DJGPP)

1. Move the distributed source to its own directory.
   Depending on your compiler, you may need to convert the source
   to have CR-LF rather than LF as line terminators.

2. If you are using Microsoft C, rename MAKEFILE.DSU to MAKEFILE.
   If you are using Borland C, rename MAKEFILE.DSB to MAKEFILE.
   If you are using DJGPP, rename MAKEFILE.DSG to MAKEFILE.

3. Look at MAKEFILE to make sure that the definitions for CC and LIBDIR
   are correct.  CC should be the name of your C compiler and
   LIBDIR should be the directory where the C libraries reside (for
   Microsoft C only).  If these definitions need to be changed, you can
   either modify the definitions directly in MAKEFILE, or set your
   environment variables CC and/or LIBDIR to override the definitions
   in MAKEFILE.

4. If you wish, you may edit DEFINES.DS to remove some optional features.
   If you choose not to include some features in your version, you may
   wish to edit the manual page LESS.MAN and the help page HELP.C
   to remove the descriptions of the features which you are removing.

5. Run your "make" program and watch the fun.
   If your "make" requires a flag to import environment variables,
   you should use that flag.
   If your compiler runs out of memory, try running "make -n >cmds.bat"
   and then run cmds.bat.

6. If the make succeeds, it will generate the programs "LESS.EXE" and
   "LESSKEY.EXE" in your current directory.  Test the generated programs.

7. When satisfied that it works, you may wish to install LESS.EXE and
   LESSKEY.EXE in a directory which is included in your PATH.



=======================================================================
INSTALLATION (Windows-95, Windows-98 and Windows-NT systems only,
              with Borland C or Microsoft Visual C++)

1. Move the distributed source to its own directory.

2. If you are using Borland C, rename Makefile.wnb to Makefile.
   If you are using Microsoft Visual C++, rename Makefile.wnm to Makefile.

3. Check the Makefile to make sure the definitions look ok.

4. If you wish, you may edit defines.wn to remove some optional features.
   If you choose not to include some features in your version, you may
   wish to edit the manual page less.man and the help page help.c
   to remove the descriptions of the features which you are removing.

5. Type "make" and watch the fun.

6. If the make succeeds, it will generate the programs "less.exe" and
   "lesskey.exe" in your current directory.  Test the generated programs.

7. When satisfied that it works, if you wish to install it
   in a public place, type "make install".
   See step 6 of the Unix installation instructions for details
   on how to change the default installation directories.



=======================================================================
INSTALLATION (OS/2 systems only,
              with EMX C)

1. Move the distributed source to its own directory.

2. Rename Makefile.o2e to Makefile.

3. Check the Makefile to make sure the definitions look ok.

4. If you wish, you may edit defines.o2 to remove some optional features.
   If you choose not to include some features in your version, you may
   wish to edit the manual page less.man and the help page help.c
   to remove the descriptions of the features which you are removing.

5. Type "make" and watch the fun.

6. If the make succeeds, it will generate the programs "less.exe" and
   "lesskey.exe" in your current directory.  Test the generated programs.

7. Make sure you have the emx runtime installed. You need the emx DLLs
   emx.dll and emxlibcs.dll and also the termcap database, termcap.dat.
   Make sure you have termcap.dat either in the default location or
   somewhere in a directory listed in the PATH or INIT environment
   variables.

8. When satisfied that it works, you may wish to install less.exe,
   lesskey.exe and scrsize.exe in a directory which is included in
   your PATH.  scrsize.exe is required only if you use a terminal
   emulator such as xterm or rxvt.



=======================================================================
INSTALLATION (OS-9 systems only,
              with Microware C or Ultra C)

1. Move the distributed source to its own directory.

2. If you are using Microware C, rename Makefile.o9c to Makefile.
   If you are using Ultra C, rename Makefile.o9u to Makefile.

3. Check the Makefile to make sure the definitions look ok.

4. If you wish, you may edit defines.o9 to remove some optional features.
   If you choose not to include some features in your version, you may
   wish to edit the manual page less.man and the help page help.c
   to remove the descriptions of the features which you are removing.

5. Type "dmake" and watch the fun.
   The standard OS-9 "make" will probably not work.  If you don't
   have dmake, you can get a copy from os9archive.rtsi.com.

6. If the make succeeds, it will generate the programs "less" and
   "lesskey" in your current directory.  Test the generated programs.

7. When satisfied that it works, if you wish to install it
   in a public place, type "dmake install".
   See step 6 of the Unix installation instructions for details
   on how to change the default installation directories.

=======================================================================
ACKNOWLEDGMENTS:
  Some versions of the less distribution are packaged using
  Info-ZIP's compression utility.
  Info-ZIP's software is free and can be obtained as source
  code or executables from various anonymous-ftp sites,
  including ftp.uu.net:/pub/archiving/zip.