From b4e5a24a3031c83ca51b50d34dea1a05aedf7b44 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Mon, 23 Dec 2019 13:41:58 +0100 Subject: Add libtar.a function to create hardlink records Signed-off-by: David Oberhollenzer --- lib/tar/write_header.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'lib/tar/write_header.c') diff --git a/lib/tar/write_header.c b/lib/tar/write_header.c index acce280..cd65f59 100644 --- a/lib/tar/write_header.c +++ b/lib/tar/write_header.c @@ -215,3 +215,53 @@ out_skip: fprintf(stderr, "WARNING: %s: %s\n", name, reason); return 1; } + +int write_hard_link(FILE *fp, const struct stat *sb, const char *name, + const char *target, unsigned int counter) +{ + tar_header_t hdr; + char buffer[64]; + size_t len; + + memset(&hdr, 0, sizeof(hdr)); + + len = strlen(target); + if (len >= 100) { + sprintf(buffer, "gnu/target%u", counter); + if (write_gnu_header(fp, sb, target, len, + TAR_TYPE_GNU_SLINK, buffer)) + return -1; + sprintf(hdr.linkname, "hardlink_%u", counter); + } else { + memcpy(hdr.linkname, target, len); + } + + len = strlen(name); + if (len >= 100) { + sprintf(buffer, "gnu/name%u", counter); + if (write_gnu_header(fp, sb, name, len, + TAR_TYPE_GNU_PATH, buffer)) { + return -1; + } + sprintf(hdr.name, "gnu/data%u", counter); + } else { + memcpy(hdr.name, name, len); + } + + write_number(hdr.mode, sb->st_mode & ~S_IFMT, sizeof(hdr.mode)); + write_number(hdr.uid, sb->st_uid, sizeof(hdr.uid)); + write_number(hdr.gid, sb->st_gid, sizeof(hdr.gid)); + write_number(hdr.size, 0, sizeof(hdr.size)); + write_number_signed(hdr.mtime, sb->st_mtime, sizeof(hdr.mtime)); + hdr.typeflag = TAR_TYPE_LINK; + memcpy(hdr.magic, TAR_MAGIC_OLD, sizeof(hdr.magic)); + memcpy(hdr.version, TAR_VERSION_OLD, sizeof(hdr.version)); + sprintf(hdr.uname, "%u", sb->st_uid); + sprintf(hdr.gname, "%u", sb->st_gid); + write_number(hdr.devmajor, 0, sizeof(hdr.devmajor)); + write_number(hdr.devminor, 0, sizeof(hdr.devminor)); + + update_checksum(&hdr); + return write_retry("writing tar hard link record", + fp, &hdr, sizeof(hdr)); +} -- cgit v1.2.3