The Machine Perception Toolbox (MPT)

00001 /*
00002  * Copyright 1994 Christopher Seiwald.
00003  *
00004  * This file is part of Jam - see jam.c for Copyright information.
00005  */
00006 
00007 /*
00008  * command.h - the CMD structure and routines to manipulate them
00009  *
00010  * Both ACTION and CMD contain a rule, targets, and sources.  An
00011  * ACTION describes a rule to be applied to the given targets and
00012  * sources; a CMD is what actually gets executed by the shell.  The
00013  * differences are due to:
00014  *
00015  *      ACTIONS must be combined if 'actions together' is given.
00016  *      ACTIONS must be split if 'actions piecemeal' is given.
00017  *      ACTIONS must have current sources omitted for 'actions updated'.
00018  *
00019  * The CMD datatype holds a single command that is to be executed 
00020  * against a target, and they can chain together to represent the 
00021  * full collection of commands used to update a target.
00022  *
00023  * Structures:
00024  *
00025  *      CMD - an action, ready to be formatted into a buffer and executed
00026  *
00027  * External routines:
00028  *
00029  *      cmd_new() - return a new CMD or 0 if too many args
00030  *      cmd_free() - delete CMD and its parts
00031  *      cmd_next() - walk the CMD chain
00032  */
00033 
00034 /*
00035  * CMD - an action, ready to be formatted into a buffer and executed
00036  */
00037 
00038 typedef struct _cmd CMD;
00039 
00040 struct _cmd
00041 {
00042         CMD     *next;
00043         CMD     *tail;          /* valid on in head */
00044         RULE    *rule;          /* rule->actions contains shell script */
00045         LIST    *shell;         /* $(SHELL) value */
00046         LOL     args;           /* LISTs for $(<), $(>) */
00047         char*   buf;    /* actual commands */
00048 } ;
00049 
00050 CMD *cmd_new(
00051         RULE    *rule,          /* rule (referenced) */
00052         LIST    *targets,       /* $(<) (freed) */
00053         LIST    *sources,       /* $(>) (freed) */
00054         LIST    *shell );       /* $(SHELL) (freed) */
00055 
00056 void cmd_free( CMD *cmd );
00057 
00058 # define cmd_next( c ) ((c)->next)