view libcommon/dispatch.c @ 47:b0cf75d0bb2d

doc/Serial-SIM-readers article written
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 21 Mar 2021 04:32:18 +0000
parents b7ee2e85686b
children
line wrap: on
line source

/*
 * This module implements common command dispatch for our SIM tools.
 */

#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include "cmdtab.h"

extern struct cmdtab cmdtab[];

static FILE *
handle_output_redir(str)
	char *str;
{
	char *cp, *fn;
	FILE *outf;

	for (cp = str; isspace(*cp); cp++)
		;
	if (!*cp || *cp == '#') {
		fprintf(stderr, "error: no filename after '>'\n");
		return(0);
	}
	for (fn = cp; *cp && !isspace(*cp); cp++)
		;
	if (*cp)
		*cp++ = '\0';
	while (isspace(*cp))
		cp++;
	if (*cp && *cp != '#') {
		fprintf(stderr, "error: invalid syntax after '>'\n");
		return(0);
	}
	outf = fopen(fn, "w");
	if (!outf)
		perror(fn);
	return outf;
}

simtool_dispatch_cmd(cmd, is_script)
	char *cmd;
{
	char *argv[20];
	char *cp, **ap;
	struct cmdtab *tp;
	FILE *outf;
	int rc;

	for (cp = cmd; isspace(*cp); cp++)
		;
	if (!*cp || *cp == '#')
		return(0);
	if (is_script)
		printf("Script command: %s\n", cp);
	if (*cp == '!')
		return system(cp + 1);
	argv[0] = cp;
	while (*cp && !isspace(*cp))
		cp++;
	if (*cp)
		*cp++ = '\0';
	for (tp = cmdtab; tp->cmd; tp++)
		if (!strcmp(tp->cmd, argv[0]))
			break;
	if (!tp->func) {
		fprintf(stderr, "error: no such command\n");
		return(-1);
	}
	for (ap = argv + 1; ; ) {
		while (isspace(*cp))
			cp++;
		if (!*cp || *cp == '#' || *cp == '>')
			break;
		if (ap - argv - 1 >= tp->maxargs) {
			fprintf(stderr, "error: too many arguments\n");
			return(-1);
		}
		if (*cp == '"') {
			*ap++ = ++cp;
			for (;;) {
				if (!*cp) {
unterm_qstring:				fprintf(stderr,
					"error: unterminated quoted string\n");
					return(-1);
				}
				if (*cp == '"')
					break;
				if (*cp++ == '\\') {
					if (!*cp)
						goto unterm_qstring;
					cp++;
				}
			}
			*cp++ = '\0';
		} else {
			*ap++ = cp;
			while (*cp && !isspace(*cp))
				cp++;
			if (*cp)
				*cp++ = '\0';
		}
	}
	if (ap - argv - 1 < tp->minargs) {
		fprintf(stderr, "error: too few arguments\n");
		return(-1);
	}
	*ap = 0;
	if (*cp == '>') {
		if (!tp->allow_redir) {
			fprintf(stderr,
			"error: command does not support output redirection\n");
			return(-1);
		}
		outf = handle_output_redir(cp + 1);
		if (!outf)
			return(-1);
	} else
		outf = stdout;
	rc = tp->func(ap - argv, argv, outf);
	if (outf != stdout)
		fclose(outf);
	return rc;
}

dispatch_ready_argv(argc, argv)
	char **argv;
{
	struct cmdtab *tp;

	for (tp = cmdtab; tp->cmd; tp++)
		if (!strcmp(tp->cmd, argv[0]))
			break;
	if (!tp->func) {
		fprintf(stderr, "error: no such command\n");
		return(-1);
	}
	if (argc - 1 > tp->maxargs) {
		fprintf(stderr, "error: too many arguments\n");
		return(-1);
	}
	if (argc - 1 < tp->minargs) {
		fprintf(stderr, "error: too few arguments\n");
		return(-1);
	}
	return tp->func(argc, argv, stdout);
}