xref: /csrg-svn/old/sdb/decode.c (revision 7773)

static	char sccsid[] = "@(#)decode.c 4.2 08/17/82";
#include "head.h"

/* decode() - read a line from standard input and decode it */

decode(p)
char *p; {
	register char c, *q;
	register int diff;
	integ = scallf = reflag = colonflag = ncolonflag = percentflag = 0;
	proc[0] = cmd = args[0] = var[0] = '\0';
	argsp = args;

	if (eqany(*p, "/?")) {	/* regular expression */
		c = *p;
		redir = (c == '/');
		reflag = 1;
		p++;
		if (*p == '\n' || *p == c) return(0);
		q = re;
		while(*p != c && *p != '\n') *q++ = *p++;
		*q = '\0';
		return(0);
	}

	if (*p == '!') { /* shell escape */
		for (q = p; *q != '\n'; q++) ;
		*q = '\0';
		system(p+1);
		return(0);
	}

	if (*p == '\n') {
		cmd = '\n';
		return(0);
	}

	if (*p == ':') {
		colonflag++;
	}

	while (*p != '\n') {	/* decode item by item */

		if (number(*p)) {	/* decimal number */
			if (integ) {
				error("Too many numbers");
				return(1);
			}
			integ = readint(&p);
			if (*p == ':') {
				ncolonflag++;
				p++;
			}
			continue;
		}

		if (varchar(*p) || eqany(*p, COMMANDS)) {
					/* proc, variable or command */
			if (cmd != '\0') {
				p = cpall(args, p);
				continue;
			}
			q = p;
			while (varchar(*q) || number(*q) || eqany(*q,COMMANDS))
				q++;
			if (*q == '(') {	/* procedure call */
				if (proc[0] != '\0') {
					error("Too many procedure calls");
					return(1);
				}
				scallf = 1;
				p = cpname(proc, p);
				p = cpall(args, p);
				continue;
			}
			if (*q == ':') {	/* procedure name */
				colonflag++;
				p = cpname(proc, p);
				continue;
			}
			if (*q == '$') {	/* variable name */
				p = cpname(var, p);
				continue;
			}
			if (((q-p == 1 && eqany(*p,COMMANDS) &&
				(proc[0]=='\0' || eqany(*p, "abcd"))) ||
				(integ && eqany(*p,COMMANDS)) ||
				 eqany(*p, "+-?"))
				&& !(*p=='-' && *(p+1) == '>'))
							{  /* command */
				cmd = *p++;
				if (eqany(cmd, "Macers")) {
					while(*p == ' ')
						p++;
					p = cpall(args, p);
				}
				continue;
			}
			/* otherwise, its a variable */
			if (var[0] != '\0') {
				error("Too many variable names");
				return(1);
			}
			p = cpname(var, p);
			if (*p == '%') {
				percentflag++;
				p++;
			}
			if (eqstr(var, ".?")) {
				var[1] = '\0';
				cmd = '?';
			}
			if (*p == '\n') {
				cmd = '/';
				continue;
			}
			if (cmd == '\0') cmd = *p ? *p : '/';
			p++;
			p = cpall(args,p);
			continue;
		}
		p++;	/* otherwise ignore p */
	}
	return(0);
}