1 files changed, 83 insertions, 0 deletions
diff --git a/src/header.c b/src/header.c
new file mode 100644
index 0000000..d881275
--- /dev/null
+++ b/src/header.c
@@ -0,0 +1,83 @@
+#include "tar.h"
+
+int	header_write(int fd, char *file_name, struct stat *statbuf)
+{
+	t_header		header;
+	struct group	*group;
+	struct passwd	*passwd;
+	unsigned int	sum;
+
+	bzero(&header, sizeof(t_header));
+	strncpy(header.file_name, file_name, sizeof(header.file_name));
+	if (S_ISDIR(statbuf->st_mode))
+		strncat(header.file_name, "/", sizeof(header.file_name) - 1);
+	sprintf(header.file_mode, "%07o", statbuf->st_mode & 0777);
+	sprintf(header.user_id,   "%07o", statbuf->st_uid);
+	sprintf(header.group_id,  "%07o", statbuf->st_gid);
+
+	if (S_ISDIR(statbuf->st_mode))
+		sprintf(header.file_size, "%011lo", 0lu);
+	else
+		sprintf(header.file_size, "%011lo", statbuf->st_size);
+
+	sprintf(header.last_time, "%011lo", statbuf->st_mtime);
+	memset(header.checksum, ' ', sizeof(header.checksum));
+
+	switch (statbuf->st_mode & S_IFMT)
+	{
+		case S_IFREG:  header.file_type[0] = '0'; break;
+		/* case S_IFLNK:  header.file_type[0] = '0' break; */
+		/* case S_IFBLK:  header.file_type[0] = '0' break; */
+		/* case S_IFCHR:  header.file_type[0] = '0' break; */
+		case S_IFDIR:  header.file_type[0] = '5'; break;
+		/* case S_IFIFO:  header.file_type[0] = '0' break; */
+		/* case S_IFSOCK: header.file_type[0] = '0' break; */
+	}
+
+	memcpy(header.ustar, "ustar ", sizeof(header.ustar));
+	memcpy(header.ustar_version, " ", sizeof(header.ustar_version));
+
+	if ((passwd = getpwuid(statbuf->st_gid)) == NULL)
+	{
+		perror("header_write getpwduid");
+		return -1;
+	}
+	strncpy(header.user_name, passwd->pw_name, sizeof(header.user_name));
+	if ((group = getgrgid(statbuf->st_gid)) == NULL)
+	{
+		perror("header_write getgrgid");
+		return -1;
+	}
+	strncpy(header.group_name, group->gr_name, sizeof(header.group_name));
+
+	sum = 0;
+	for (size_t i = 0; i < sizeof(t_header); i++)
+		sum += ((uint8_t*)&header)[i];
+	sprintf(header.checksum,  "%06o", sum);
+
+	return record_write(fd, (char*)&header, sizeof(t_header));
+}
+
+int header_parse(char record[RECORD_SIZE], struct stat *statbuf, t_header *header)
+{
+	unsigned int	actual_checksum;
+	unsigned int	expected_checksum;
+
+	memcpy(header, record, sizeof(t_header));
+
+	actual_checksum = -1;
+	sscanf(header->checksum, "%06o", &actual_checksum);
+	memset(header->checksum, ' ', 8);
+	expected_checksum = 0;
+	for (size_t i = 0; i < sizeof(t_header); i++)
+		expected_checksum += ((uint8_t*)header)[i];
+	if (actual_checksum != expected_checksum)
+		return -1;
+
+	sscanf(header->file_mode, "%07o", &statbuf->st_mode);
+	sscanf(header->user_id,   "%07o", &statbuf->st_uid);
+	sscanf(header->group_id,  "%07o", &statbuf->st_gid);
+	sscanf(header->file_size, "%011lo", (long unsigned int*)&statbuf->st_size);
+	sscanf(header->last_time, "%011lo", (long unsigned int*)&statbuf->st_mtime);
+	return 0;
+}