git.y1.nz

main.c

#include <stdio.h> /* printf */
#include <string.h> /* strlen */
#include <unistd.h> /* execlp, access */
#include <sys/wait.h> /* waitpid */
#include <stdlib.h> /* exit */
#include <errno.h> /* errno */
#include <fcntl.h> /* creat */

#include "okra.h"
#include "config.h"

#define FATAL(message) { \
	printf("\033[1;31m" "Fatal: " message "\033[0m" "\n"); \
	exit(1); \
}
#define FORKEXEC(arg1, ...)  { \
	pid = fork(); \
	if (!pid) { \
		int result; \
		result = execlp(arg1, arg1, __VA_ARGS__, NULL); \
		exit(0); \
	} \
	waitpid(pid, &child_status, 0); \
}
#define FFORKEXEC(fname, arg1, ...)  { \
	pid = fork(); \
	if (!pid) { \
		int result; \
		int fd = creat( \
			fname, \
			O_CREAT | O_TRUNC | O_WRONLY | \
			S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH \
		); \
		if (fd == -1) { \
			printf("Failed to create [%s]" "\n", fname); \
			FATAL("couldnt open/create file :("); \
		} \
		dup2(fd, STDOUT_FILENO); \
		result = execlp(arg1, arg1, __VA_ARGS__, NULL); \
		if (result == -1) { \
			int err = errno; \
			FATAL("Uh oh exec dint work :(("); \
		} \
		exit(0); \
	} \
	waitpid(pid, &child_status, 0); \
}

pid_t pid;
int child_status;

void
ask_to_continue()
{
	char ch;

	// TODO set termios so it's "press y to %s, n or q to quit"
	printf("Try again?"); fflush(stdout);
	for (;;) {
		switch (getchar()) {
		case 'y': return;
		case 'n':
		case 'q': FATAL("Cancelled.");
		}
	}
}

void
ensure_file_exists(const char *path)
{
	if (!access(path, O_RDONLY)) return;
	printf("Couldn't access local file [%s]" "\n", path);
	FATAL("File is inaccessible");
}

int
streq(const char *a, const char *b)
{
	if (a == NULL && b == NULL) return 1;
	if (a == NULL || b == NULL) return 0;
	int i = 0;
	for (;;) {
		if (a[i] != b[i]) return 0;
		if (a[i] == '\0') return 1;
		i++;
	}
}

const char *
get_extension(const char *filename)
{
	int length = strlen(filename);
	int i = length-1;
	for (;;) {
		i--;
		if (i < 0) return NULL;
		if (filename[i] == '.')
			return filename + (i+1);
	}
}

const char *
get_raw_file(OkraUri *uri)
{
	const char *ret = NULL;

	/* default to "file" scheme */
	if (uri->scheme == NULL || streq(uri->scheme, "file"))
		return uri->path;

	if (streq(uri->scheme, "mailto"))
		FATAL("TODO open a mail client then exit?");

	if (streq(uri->scheme, "http") || streq(uri->scheme, "https")) {
		child_status = 1;
		ret = DEFAULT_SESSION_DIR "/current.html";
		for (;;) {
			if (child_status == 0) break;
			FFORKEXEC(ret, "wget", "-O", "-", uri->uri);
			if (child_status != 0) {
				printf("Exit status was %d" "\n", child_status);
				ask_to_continue();
			}
		}
		return ret;
	}

	if (streq(uri->scheme, "gopher")) {
		ret = DEFAULT_SESSION_DIR "/current.gph";
		FFORKEXEC(ret, "hurl", uri->uri);
		return ret;
	}

	if (streq(uri->scheme, "ftp"))
		FATAL("TODO retrieve ftp page.");

	printf("Scheme: [%s]" "\n", uri->scheme);
	FATAL("Unhandled scheme.");
	exit(1);
}

const char *
get_digested_file(OkraUri *uri, const char *raw_file)
{
	const char *ret = NULL;
	const char *ext = get_extension(uri->uri);

	if (streq(ext, "txt")) return raw_file;

	if (streq(ext, "html")) {
		ret = DEFAULT_SESSION_DIR "/current.md";
		FORKEXEC(
			"digest-html",
			"-b", uri->uri,
			"-o", ret,
			raw_file
		);
		if (child_status != 0) FATAL("Failed to digest HTML.");
		return ret;
	}

	if (streq(ext, "gph")) {
		ret = DEFAULT_SESSION_DIR "/current.md";
		FORKEXEC("digest-gopher", "-o", ret, raw_file);
		if (child_status != 0) FATAL("Failed to digest gohper.");
		return ret;
	}

	/* default based on scheme */
	// TODO is there a better way?
	if (streq(uri->scheme, "http") || streq(uri->scheme, "https")) {
		ret = DEFAULT_SESSION_DIR "/current.md";
		FORKEXEC(
			"digest-html",
			"-b", uri->uri,
			"-o", ret,
			raw_file
		);
		if (child_status != 0) FATAL("Failed to digest HTML.");
		return ret;
	}
	if (streq(uri->scheme, "gopher")) {
		ret = DEFAULT_SESSION_DIR "/current.md";
		FORKEXEC("digest-gopher", "-o", ret, raw_file);
		if (child_status != 0) FATAL("Failed to digest gopher.");
		return ret;
	}

	printf("No digester, defaulting to raw" "\n");
	return raw_file;
}

int
main(int argc, const char *argv[])
{
	if (argc != 2) {
		printf("Usage: %s URI" "\n", argv[0]);
		return 1;
	}

	OkraUri *uri = okra_parse(argv[1]);
	if (uri == NULL) FATAL("Invalid URI.");

	FORKEXEC("rm", "-f", "current.md", "current.gph", "current.html");

	const char *raw_file = get_raw_file(uri);
	if (raw_file == NULL) FATAL("No file to view.");
	ensure_file_exists(raw_file);

	const char *lwl_file = get_digested_file(uri, raw_file);
	ensure_file_exists(lwl_file);
	FORKEXEC("lwl", lwl_file);

	okra_free(uri);
}

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