gawk

commit e9b871ac8026cc918d4c3939212a49d37a49363f
parent ddf2f68743bb0a445bdec3b440d5ac2abcbcb276
Author: Jacob R. Edwards <jacobouno@protonmail.com>
Date:   Sat, 19 Dec 2020 01:38:35 -0800

Add dysfunctional and badly written program

It is not yet quite, functional, but is mostly what I want out of
it.

Diffstat:
M
main.c
 | 
184
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---

1 file changed, 178 insertions(+), 6 deletions(-)
diff --git a/main.c b/main.c
@@ -23,6 +23,12 @@
 #include <string.h>
 #include <err.h>
 #include <errno.h>
+#include <limits.h>
+#include <ctype.h>
+
+#define LEN(X) (sizeof(X) / sizeof(*X))
+
+#define PROTO_MAX 16
 
 int
 resolve(struct addrinfo **ai, const char *host, const char *proto)
@@ -49,7 +55,7 @@ connect_to(const char *host, const char *proto)
 
 	error = resolve(&ai0, host, proto);
 	if (error) {
-		warnx("Unable to resolve '%s':", gai_strerror(error));
+		warnx("Unable to resolve: %s:", gai_strerror(error));
 		return -1;
 	}
 
@@ -75,14 +81,180 @@ connect_to(const char *host, const char *proto)
 	return s;
 }
 
+char *
+input(char *buf, int size, const char *prompt, FILE *fp)
+{
+	int len;
+	char *r;
+
+	fputs(prompt, stdout);
+	r = fgets(buf, size, fp);
+	if (r == NULL)
+		return NULL;
+
+	len = strlen(buf);
+	if (len >= size && buf[size - 1] != '\n')
+		warnx("maximum of %d bytes: Input too large.", size);
+	else if (len > 0)
+		buf[len - 1] = '\0';
+	
+	return r;
+}
+
+void
+update_prompt(char *prompt, size_t size, const char *host, const char *path, int connected)
+{
+	snprintf(prompt, size, "%s%s %c> ",
+	    host, path, connected ? '+' : '-');
+}
+
+int
+strtoui(const char *s)
+{
+	int i;
+
+	i = 0;
+	while (isdigit(*s)) {
+		i = i * 10 + (*s - '0');
+		++s;
+	}
+	if (*s != '\0')
+		return -1;
+	return i;
+}
+
+void
+newpath(char *path, char *newpath)
+{
+	size_t len;
+
+	if (*newpath == '/') {
+		strlcpy(path, newpath, PATH_MAX);
+	} else {
+		len = strlen(path);
+		if (len > 0 && path[len - 1] != '/')
+			path[len - 1] = '/';
+		strncat(path, newpath, PATH_MAX);
+	}
+}
+
+void
+gawkparse(char *cmd, char *host, char *path, char *port)
+{
+	int i;
+	char *parts[3];
+	char *nhost, *npath, *nport;
+
+	nhost = host;
+	npath = path;
+	nport = port;
+
+	for (i = 0; i < 3; ++i)
+		parts[i] = strsep(&cmd, ":");
+
+	if (parts[1] == NULL) {
+		if (parts[0] != NULL)
+			npath = parts[0];
+	} else {
+		if (parts[2] != NULL)
+			nport = parts[2];
+		nhost = parts[0];
+		npath = parts[1];
+	}
+
+	strlcpy(host, nhost, HOST_NAME_MAX);
+	newpath(path, npath);
+	strlcpy(port, nport, PROTO_MAX);
+}
+
+/* returns `<0` on error, if positive `n - 1` is
+ * be returned to the caller. */
+int
+gawk(int sock, int depth, const char *host, const char *path, const char *port)
+{
+	int done;
+	int child;
+	char cbuf[PATH_MAX + HOST_NAME_MAX + PROTO_MAX];	
+	char *cmd;
+	char npath[PATH_MAX];
+	char nhost[HOST_NAME_MAX];
+	char nport[PROTO_MAX];
+	char prompt[64];
+
+	++depth;
+
+	child = -1;
+	done = 0;
+	update_prompt(prompt, sizeof(prompt), host, path, sock != -1);
+	while (!done && (cmd = input(cbuf, sizeof(cbuf), prompt, stdin))) {
+		if (*cmd == '\0')
+			continue;
+
+		switch (*cmd++) {
+		case 'g':
+			if (*cmd == '\0') {
+				warnx("'g': No arguments.");
+				break;;
+			}
+
+			gawkparse(cmd, nhost, npath, nport);
+			if (strcmp(host, nhost) != 0 && strcmp(port, nport) != 0) {
+				done = gawk(child, depth, nhost, npath, nport);
+			} else {
+				child = connect_to(nhost, nport);
+				if (child == -1) {
+					warn("unable to connect '%s' '%s'", nhost, nport);
+					break;
+				}
+
+				done = gawk(child, depth, nhost, npath, nport);
+
+				if (close(child) == -1) {
+					warn("unable to close '%s' '%s'", nhost, npath);
+					return -1;
+				}
+			}
+
+			break;
+		case 'b':
+			if (*cmd == '\0')
+				done = 1;
+			else {
+				done = strtoui(cmd);
+				if (done < 0) {
+					warnx("invalid argument for 'b', '%s'", cmd);
+					done = 0;
+				}
+			}
+			break;
+		case 'c':
+			if (sock != -1) {
+				warnx("already connected");
+				break;
+			}
+			sock = connect_to(host, port);
+			update_prompt(prompt, sizeof(prompt), host, prompt, sock != -1);
+			break;
+		case 'q':
+			if (*cmd != '\0')
+				warnx("'q': Takes no arguments.");
+			done = depth;
+			break;
+		default:
+			warnx("invalid command '%c'", *--cmd);
+		}
+	}
+	if (ferror(stdin)) {
+		warn("an error ocoured on stdin");
+		return -1;
+	}
+	return done - 1;
+}
+
 int
 main(int argc, char *argv[])
 {
-	int s;
+	gawk(-1, 0, "localhost", "/","gopher");
 
-	s = connect_to("localhost", "gopher");
-	if (s == -1)
-		return 1;
-	close(s);
 	return 0;
 }