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CPM OPERATING SYSTEMS/CPM 68K/1.0X SOURCES/v101/klib/main.c

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+/*****************************************************************************
+*
+*		R U N T I M E   S T A R T O F F   R O U T I N E
+*		-----------------------------------------------
+*
+*	Routine "_main" is entered from the C header routine to start a C 
+*	program.  The command string from CP/M is parsed into
+*	a UNIX-like "argc/argv" setup, including simple I/O redirection.
+*
+*	Calling Sequence:
+*
+*		return = _main(command,length);
+*
+*	Where:
+*
+*		command		Is the address of the command line from CP/M
+*		length		Is the number of characters in the line, 
+*				excluding the termination character (CR/LF).
+*
+*****************************************************************************/
+#include "stdio.h"				/* Include std definitions  */
+#include "cpm.h"				/* Include CP/M Definitions */
+extern	char	__tname[];			/* -> terminal name	    */
+extern	char	__pname[];			/* -> Program name	    */
+_main(com, len)					/****************************/
+	char 	*com;				/* Command address	    */
+	int	len;				/* Command length	    */
+{						/****************************/
+	char	*av[30];			/* Unix's "ARGV" for main   */
+	register i;				/* Define a count var.	    */
+	register char *s;			/* Temp byte pointer	    */
+	int	 ac;				/* Number of args we find   */
+						/****************************/
+	_chinit();				/* Initialize channels	    */
+	open(__tname,READ);			/* Open STDIN		    */
+	open(__tname,WRITE);			/* Open STDOUT		    */
+	open(__tname,WRITE);			/* Open STDERR		    */
+	av[0] = __pname;			/*			    */
+	com[len] = '\0';			/* Insure null at line end  */
+	ac = 1;					/* Initialize count	    */
+	for (s = com; *s; s =+ i)		/* One arg at a time	    */
+	{					/*			    */
+		while (*s && iswhite(*s))	/* Skip leading spaces	    */
+			++s;			/*			    */
+		if (!*s)			/* End of line?		    */
+			break;			/* Yes, don't continue	    */
+		for (i = 0; !iswhite(s[i]); ++i)/* How many characters?	    */
+			s[i] = tolower(s[i]);	/* lower case please ...    */
+		if (s[i])			/* If last is space, etc... */
+			s[i++] = '\0';		/* Make it a null for C	    */
+						/****************************/
+		if (*s == '<')			/* Redirecting input??	    */
+		{				/*			    */
+		  close(STDIN);			/* Yes, close TTY	    */
+		  if (open(s + 1, READ,0) != STDIN) /* Open New		    */
+		    _err("Cannot open ", s + 1)	;/*  Can't ...		    */
+		}				/****************************/
+		else if (*s == '>')		/* Redirecting output??	    */
+		{				/*			    */
+		  close(STDOUT);		/* Close output		    */
+		  if (creat(s+1,0,0)!=STDOUT)	/* Try to open new	    */
+		    _err("Cannot create ", s + 1);/*	Can't		    */
+		}				/****************************/
+		else				/* Just a regular arg	    */
+			av[ac++] = s;		/* save in argv		    */
+	}					/****************************/
+	av[ac] = NULL;				/* Insure terminator	    */
+	return (main(ac, av));			/* Invoke C program	    */
+}						/****************************/
+
+_err(s1,s2)					/* Error routine	    */
+	char	*s1;				/* Message text		    */
+	char	*s2;				/* Filename		    */
+{						/****************************/
+	write(STDERR,s1,_clenf(s1));		/* Output error message	    */
+	write(STDERR,s2,_clenf(s2));		/* And filename		    */
+	write(STDERR,"\n",1);			/* + Newline		    */
+	exit(-1);				/* And fail hard	    */
+}						/****************************/