bionic (1) shc.1.gz

NAME

       shc - Generic shell script compiler

SYNOPSIS

       shc [ -e date ] [ -m addr ] [ -i iopt ] [ -x cmnd ]
       [ -l lopt ] [ -ACDhTv ] -f script

DESCRIPTION

       shc creates a stripped binary executable version of the script specified with -f on the command line.

       The  binary  version  will  get a .x extension appended and will usually be a bit larger in size than the
       original ascii code.  Generated C source code is saved in a file with the extension .x.c

       If you supply an expiration date with the -e option the compiled binary will refuse to run after the date
       specified.   The  message  "Please contact your provider" will be displayed instead.  This message can be
       changed with the -m option.

       You can compile any kind of shell script, but you need to supply valid -i, -x and -l options.

       The compiled binary will still be dependent on the shell specified in the first line of  the  shell  code
       (i.e. #!/bin/sh), thus shc does not create completely independent binaries.

       shc  itself  is  not a compiler such as cc, it rather encodes and encrypts a shell script and generates C
       source code with the added expiration capability. It then uses the system compiler to compile a  stripped
       binary  which  behaves exactly like the original script. Upon execution, the compiled binary will decrypt
       and execute the code with the shell -c option.  Unfortunately, it will not give you any speed improvement
       as a real C program would.

       shc's  main  purpose  is to protect your shell scripts from modification or inspection. You can use it if
       you wish to distribute your scripts but don't want them to be easily readable by other people.

OPTIONS

       The command line options are:

       -e date
              Expiration date in dd/mm/yyyy format [none]

       -m message
              message to display upon expiration ["Please contact your provider"]

       -f script_name
              File name of the script to compile

       -i inline_option
              Inline option for the shell interpreter i.e: -e

       -x command
              eXec command, as a printf format i.e: exec(\\'%s\\',@ARGV);

       -l last_option
              Last shell option i.e: --

       -r     Relax security. Make a redistributable binary which executes on different systems running the same
              operating system.

       -v     Verbose compilation

       -D     Switch on debug exec calls

       -T     Allow binary to be traceable (using strace, ptrace, truss, etc.)

       -C     Display license and exit

       -A     Display abstract and exit

       -h     Display help and exit

ENVIRONMENT VARIABLES

       CC     C compiler command [cc]

       CFLAGS C compiler flags [none]

EXAMPLES

       Compile a script which can be run on other systems with the trace option enabled:

         example% shc -v -r -T -f myscript

BUGS

       The  maximum  size  of the script that could be executed once compiled is limited by the operating system
       configuration parameter _SC_ARG_MAX (see sysconf(2))

AUTHOR

       Francisco Rosales <frosal@fi.upm.es>

REPORT BUGS TO

       the author.