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#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;
}
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