strliteral.c

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>

static void make_identifier(char *str) {
	char c;
	size_t i;
	for (i = 0; (c = str[i]) != '\0'; ++i) {
		if (!(
				(c >= '0' && c <= '9') ||
				(c >= 'a' && c <= 'z') ||
				(c >= 'A' && c <= 'Z'))) {
			str[i] = '_';
		}
	}
}

/* strdup is actually a POSIX thing, not a C thing, so don't use it */
static char *dupstr(char *str) {
	size_t len = strlen(str);
	char *dup = malloc(len + 1);
	strcpy(dup, str);
	dup[len] = '\0';
	return dup;
}

static void usage(const char *argv0) {
	printf("Usage: %s [options] [infile] [outfile]\n", argv0);
	puts(
			"Options:\n"
			"\t-h, --help                  Show this help text\n"
			"\t--no-const                  Output mutable variables instead of consts\n"
			"\t--always-escape             Unconditionally escape every character\n"
			"\t-l, --line-length <length>  Specify how long a line should be\n"
			"\t-i, --ident <ident>         Overwrite the identifier instead of using the file name");
}

int main(int argc, char **argv) {
	int ret = 0;
	char *inp = "stdin", *outp = "stdout";
	FILE *inf = stdin, *outf = stdout;
	char *ident = NULL;
	char *buffer = NULL;
	char *conststr = "const ";
	int alwaysescape = 0;
	size_t maxlength = 100;

	int argidx;
	for (argidx = 1; argidx < argc; ++argidx) {
		char *arg = argv[argidx];
		if (arg[0] != '-' || strcmp(arg, "--") == 0) {
			break;
		}

		if (strcmp(arg, "--help") == 0 || strcmp(arg, "-h") == 0) {
			usage(argv[0]);
			goto exit;
		} else if (strcmp(arg, "--no-const") == 0) {
			conststr = "";
		} else if (strcmp(arg, "--always-escape") == 0) {
			alwaysescape = 1;
		} else if (strcmp(arg, "--line-length") == 0 || strcmp(arg, "-l") == 0) {
			if (argidx + 1 >= argc) {
				fprintf(stderr, "%s requires an argument\n", arg);
				goto fail;
			}
			maxlength = (size_t)atoi(argv[++argidx]);
		} else if (strcmp(arg, "--ident") == 0 || strcmp(arg, "-i") == 0) {
			if (argidx + 1 >= argc) {
				fprintf(stderr, "%s requires an argument\n", arg);
				goto fail;
			}
			ident = dupstr(argv[++argidx]);
			make_identifier(ident);
		} else {
			fprintf(stderr, "Unknown option: %s\n", arg);
			usage(argv[0]);
			goto fail;
		}
	}

	if (argc - argidx == 0) {
		if (ident == NULL) {
			ident = dupstr("stdin");
		}
	} else if (argc - argidx == 1 || argc - argidx == 2) {
		inp = argv[argidx];
		inf = fopen(inp, "rb");
		if (inf == NULL) {
			perror(inp);
			goto fail;
		}

		if (ident == NULL) {
			ident = dupstr(inp);
			make_identifier(ident);
		}

		if (argc - argidx == 2) {
			outp = argv[argidx + 1];
			outf = fopen(outp, "w");
			if (outf == NULL) {
				perror(outp);
				goto fail;
			}
		}
	} else {
		fprintf(stderr, "Unexpected number of non-option arguments: %i\n", argc - argidx);
		goto fail;
	}

	if (fprintf(outf, "%sunsigned char %s[] =\n\t\"", conststr, ident) < 0) {
		perror("write d");
		goto fail;
	}

	buffer = malloc(maxlength + 4);

	size_t linechar = 0;
	size_t length = 0;
	int c;
	while ((c = fgetc(inf)) != EOF) {
		if (alwaysescape) {
			buffer[linechar++] = '\\';
			buffer[linechar++] = '0' + ((c & 0700) >> 6);
			buffer[linechar++] = '0' + ((c & 0070) >> 3);
			buffer[linechar++] = '0' + ((c & 0007) >> 0);
		} else if (c >= 32 && c <= 126 && c != '"' && c != '\\' && c != '?' && c != ':' && c != '%') {
			buffer[linechar++] = (char)c;
		} else if (c == '\r') {
			buffer[linechar++] = '\\';
			buffer[linechar++] = 'r';
		} else if (c == '\n') {
			buffer[linechar++] = '\\';
			buffer[linechar++] = 'n';
		} else if (c == '\t') {
			buffer[linechar++] = '\\';
			buffer[linechar++] = 't';
		} else if (c == '\"') {
			buffer[linechar++] = '\\';
			buffer[linechar++] = '"';
		} else if (c == '\\') {
			buffer[linechar++] = '\\';
			buffer[linechar++] = '\\';
		} else {
			buffer[linechar++] = '\\';
			buffer[linechar++] = '0' + ((c & 0700) >> 6);
			buffer[linechar++] = '0' + ((c & 0070) >> 3);
			buffer[linechar++] = '0' + ((c & 0007) >> 0);
		}

		length += 1;

		if (linechar >= maxlength) {
			if (fwrite(buffer, 1, linechar, outf) != linechar) {
				perror("write");
				goto fail;
			}

			if (fwrite("\"\n\t\"", 1, 4, outf) != 4) {
				perror("write");
				goto fail;
			}

			linechar = 0;
		}
	}

	if (linechar >= 1) {
		if (fwrite(buffer, 1, linechar, outf) != linechar) {
			perror("write b");
			goto fail;
		}
	}

	if (ferror(inf)) {
		perror("read");
		goto fail;
	}

	if (fprintf(outf, "\";\n%sunsigned int %s_len = %u;\n",
				conststr, ident, (unsigned int)length) < 0) {
		perror("write c");
		goto fail;
	}

	if (fclose(inf) == EOF) {
		perror("close");
		goto fail;
	}

	if (fclose(outf) == EOF) {
		perror("close");
		goto fail;
	}

exit:
	free(ident);
	free(buffer);
	return ret;

fail:
	ret = 1;
	goto exit;
}