ZIP_FILE_GET_EXTERNAL_ATTRIBUTES(3) | Library Functions Manual | ZIP_FILE_GET_EXTERNAL_ATTRIBUTES(3)

# NAME

`zip_file_get_external_attributes` —
get external attributes for file in zip

# LIBRARY

libzip (-lzip)

# SYNOPSIS

`#include <zip.h>`

int
`zip_file_get_external_attributes`(zip_t *archive, zip_uint64_t index, zip_flags_t flags, zip_uint8_t *opsys, zip_uint32_t *attributes);

# DESCRIPTION

The `zip_file_get_external_attributes`() function returns the operating system and external attributes for the file at position index in the zip archive. The external attributes usually contain the operating system-specific file permissions. If flags is set to `ZIP_FL_UNCHANGED`, the original unchanged values are returned. If opsys or attributes are `NULL`, they are not filled in.

The following operating systems are defined by the zip specification:

- `ZIP_OPSYS_ACORN_RISC`
- `ZIP_OPSYS_ALTERNATE_MVS`
- `ZIP_OPSYS_AMIGA`
- `ZIP_OPSYS_ATARI_ST`
- `ZIP_OPSYS_BEOS`
- `ZIP_OPSYS_CPM`
- `ZIP_OPSYS_DOS`
- `ZIP_OPSYS_MACINTOSH`
- `ZIP_OPSYS_MVS`
- `ZIP_OPSYS_OPENVMS`
- `ZIP_OPSYS_OS_2`
- `ZIP_OPSYS_OS_400`
- `ZIP_OPSYS_OS_X`
- `ZIP_OPSYS_TANDEM`
- `ZIP_OPSYS_UNIX`
- `ZIP_OPSYS_VFAT`
- `ZIP_OPSYS_VM_CMS`
- `ZIP_OPSYS_VSE`
- `ZIP_OPSYS_WINDOWS_NTFS` (uncommon, use `ZIP_OPSYS_DOS` instead)
- `ZIP_OPSYS_Z_SYSTEM`

The defines above follow the PKWARE Inc. Appnote; please note that the InfoZIP Appnote has a slightly different mapping.

# RETURN VALUES

Upon successful completion, 0 is returned. In case of an error, `-1` is returned and the error code in archive is set to indicate the error.

# EXAMPLES

The following code can be used to expand attributes if the operating system is `ZIP_OPSYS_DOS`.

    #include <sys/stat.h>

    #define FA_RDONLY       0x01            // FILE_ATTRIBUTE_READONLY
    #define FA_DIREC        0x10            // FILE_ATTRIBUTE_DIRECTORY

    static mode_t
    _zip_dos_attr2mode(zip_uint32_t attr)
    {
       mode_t m = S_IRUSR | S_IRGRP | S_IROTH;
       if (0 == (attr & FA_RDONLY))
          m |= S_IWUSR | S_IWGRP | S_IWOTH;

       if (attr & FA_DIREC)
          m = (S_IFDIR | (m & ~S_IFMT)) | S_IXUSR | S_IXGRP | S_IXOTH;

       return m;
    }

# ERRORS

`zip_file_get_external_attributes`() fails if:

[`ZIP_ER_INVAL`]
  index is not a valid file index in archive.

# SEE ALSO

libzip(3), zip_file_set_external_attributes(3)

# HISTORY

`zip_file_get_external_attributes`() was added in libzip 0.11.2.

# AUTHORS

Dieter Baron <dillo@nih.at> and Thomas Klausner <wiz@gatalith.at>

December 18, 2017 | NiH