GNO_COMMAND(3)                 Library Routines                 GNO_COMMAND(3)




NAME

       ~GNO_COMMAND,  ~GNO_PARSEARG,  ~GNO_FREEARG  - command line parsing and
       startup from assembly code


SYNOPSIS

       ~GNO_COMMAND
       ~GNO_PARSEARG subroutine (4:commandline,4:argptr)
       ~GNO_FREEARG subroutine (4:argv,2:argc)


DESCRIPTION

       ~GNO_COMMAND emulates the startup code of a C program, and  acts  as  a
       wrapper  for  the  ~GNO_PARSEARG and ~GNO_FREEARG functions, below.  To
       use this routine, immediately execute a JML to ~GNO_COMMAND  from  your
       first  segment.  Ensure you have a function main() that conforms to the
       following C prototype:

            int main (int argc, char **argv);

       ~GNO_PARSEARG will take the command line passed to a utility and  parse
       it  into  an  argc, argv structure like those used in C programs.  This
       was written not as a replacement for a C parser, but for use by  assem-
       bly language programmers writing shell commands.

       commandline  is  the  raw  command line string as passed by the calling
       shell in the X and Y registers.  argptr is a pointer to an argv[]-style
       array.

       ~GNO_FREEARG  frees  the  region  allocated by ~GNO_PARSEARG.  argv and
       argc should be the region pointed to by argptr and the return value  of
       ~GNO_PARSEARG, respectively.


RETURN VALUE

       ~GNO_COMMAND returns in the accumulator the value returned by main().

       ~GNO_PARSEARG returns in the accumulator the number of arguments found.

       ~GNO_FREEARG does not return a value.


HISTORY

       These routines first appeared in GNO v1.0.  They are  based  on  actual
       gsh(1) parsing code.


CAVEATS

       ~GNO_PARSEARG  assumes  that  the  ByteWorks  Memory  Manager  has been
       started up and is usable.  No such assumption is  made  with  ~GNO_COM-
       MAND.



GNO                             27 January 1997                 GNO_COMMAND(3)

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