first commit

1 files changed, 238 insertions, 0 deletions

diff --git a/pages.c b/pages.c
new file mode 100644
index 0000000..742ef7c
--- /dev/null
+++ b/pages.c
@@ -0,0 +1,238 @@
+/*
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ *(at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "pages.h"
+#include "config.h"
+
+int
+createfile(const char *file)
+{
+	/*
+	 * create file at location 'file' using the template
+	 * overwrite if it exists
+	 * assume the caller has put us in the base directory already
+	 */
+	
+	struct stat sb = {0};
+
+	if(!stat(output_dir, &sb) == 0 && !S_ISDIR(sb.st_mode))
+	{
+		fprintf(stderr, "directory '%s' does not exist, trying to make directory..\n", output_dir);
+		if (mkdir(output_dir, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) != 0)
+		{
+			fprintf(stderr, "unable to mkdir '%s', unrecoverable failure\n", output_dir);
+			return 0;
+		}
+		fprintf(stderr, "OK\n");
+	}
+	char filename[512] = {0};
+	size_t length = 512;
+	strncat(filename, output_dir, length-1);
+	length = length - strlen(output_dir);
+	strncat(filename, file, length-1);
+
+	FILE *out = fopen(filename, "w");
+	if (!out)
+	{
+
+		fprintf(stderr, "unable to open file '%s', unrecoverable failure\n", filename);
+		return 0;
+	}
+
+	FILE *in = fopen(template_file, "r");
+	if (!in)
+	{
+		fprintf(stderr, "unable to open file '%s', unrecoverable failure\n", filename);
+		fclose(out);
+		return 0;
+	}
+
+	char c;
+
+	while ((c = fgetc(in)) != EOF)
+	{
+		fputc(c, out);
+	}
+
+	fclose(out);
+	fclose(in);
+	return 1;
+}
+
+long
+findstring(const char *file, const char *str)
+{
+	/*
+	 * find first occurance of substring 'str' in file 'output_dir'/'file'
+	 * return offset of string beginning
+	 * -1 on error (including not found)
+	 *  
+	 *  return value is a long obtained by ftell(), set the position later using fseek()
+	 *  (use SEEK_SET as whence for beginning of file)
+	 */
+
+	long offset = -1;
+
+	char filename[512] = {0};
+	size_t length = 512;
+	strncat(filename, output_dir, length-1);
+	length = length - strlen(output_dir);
+	strncat(filename, file, length-1);
+
+	FILE *in = fopen(filename, "r");
+	if (!in)
+	{
+		fprintf(stderr, "unable to open file '%s', unrecoverable failure\n", filename);
+		return -1;
+	}
+
+	/* hacky */
+	char buffer[1024] = {0};
+	char *strpos = NULL;
+	while (fgets(buffer, 1024, in) != NULL)
+	{
+		strpos = strstr(buffer, str);
+		if (strpos)
+		{
+			/* found our substring */
+			break;
+		}
+		memset(buffer, 0, 1024);
+		continue;
+	}
+	if (!strpos)
+	{
+		fprintf(stderr, "unable to find substring '%s' in '%s'\n", str, filename);
+		fclose(in);
+		return -1;
+	}
+	
+	/* we have the line that holds our substring, find out where it is in the file */
+	long curpos = ftell(in);
+	if (!curpos)
+	{
+		fprintf(stderr, "ftell() failed\n");
+		fclose(in);
+		return -1;
+	}
+	// strpos-buffer = first byte of str in line
+	offset = (curpos - strlen(buffer)+1) + strpos-buffer;
+
+	fclose(in);
+	return offset;
+}
+
+int
+deletebytes(const char *file, long offset, size_t bytes)
+{
+	/*
+	 * delete 'bytes' bytes from 'output_dir'/'file' starting at offset 'offset'
+	 * return 1 on success. 0 on failure
+	 */
+
+	char filename[512] = {0};
+	size_t length = 512;
+	strncat(filename, output_dir, length-1);
+	length = length - strlen(output_dir);
+	strncat(filename, file, length-1);
+
+	FILE *in = fopen(filename, "r");
+	if (!in)
+	{
+		fprintf(stderr, "unable to open file '%s', unrecoverable failure\n", filename);
+		return 0;
+	}
+
+	FILE *out = tmpfile();
+	if (!out)
+	{
+		fprintf(stderr, "unable to open temporary file, unrecoverable failure\n");
+		fclose(in);
+		return 0;
+	}
+
+	long curpos = 1;
+	char c;
+	/* read bytes from 'in' and write them to 'out', skipping 'bytes' bytes starting at 'offset' */
+	while ((c = fgetc(in)) != EOF)
+	{
+		if (curpos >= offset && curpos <= ((offset-1)+bytes))
+		{
+			; // byte is one we want to skip
+		}
+		else
+			fputc(c, out);
+
+		curpos++;
+	}
+
+	/* delete 'filename' and move our temp file 'out' to take its place (by naively rewriting the file..) */
+	fclose(in);
+	if (remove(filename) == -1) 
+	{
+
+		fprintf(stderr, "unable to delete file '%s', unrecoverable failure\n", filename);
+		fclose(out);
+		return 0;
+	}
+
+	/* FIXME: do something better than rewriting the file, move it somehow */
+	FILE *new = fopen(filename, "w");
+	if (!new)
+	{
+		fprintf(stderr, "unable to open file '%s' for writing new data, unrecoverable failure\n", filename);
+		fclose(out);
+		return 0;
+	}
+	fseek(out, 0, SEEK_SET);
+	while ((c = fgetc(out)) != EOF)
+	{
+		fputc(c, new);
+	}
+
+	fclose(out);
+	fclose(new);
+	return 1;
+}
+
+int
+frontpage(int flags)
+{
+	if (!createfile(frontpage_index_output))
+	{
+		fprintf(stderr, "unable to generate frontpage\n");
+		return 0;
+	}
+
+	long substrpos = -1;
+
+	substrpos = findstring(frontpage_index_output, "cirno");
+
+	if (substrpos < 0)
+	{
+		fprintf(stderr, "unable to generate frontpage\n");
+		return 0;
+	}
+
+	printf("first occurance of '%s' is at byte %ld\n", "cirno", substrpos);
+
+	
+	if (!deletebytes(frontpage_index_output, substrpos, strlen("cirno")))
+	{
+		fprintf(stderr, "unable to generate frontpage\n");
+		return 0;
+	}
+	return 1;
+}