MAGIC(3)                 BSD Library Functions Manual                 MAGIC(3)

NAME
     magic_open, magic_close, magic_error, magic_file,
     magic_buffer, magic_setflags, magic_check, magic_compile,
     magic_load -- Magic number recognition library.

LIBRARY
     Magic Number Recognition Library (libmagic, -lmagic)

SYNOPSIS
     #include <magic.h>

     magic_t
     magic_open(int flags);

     void
     magic_close(magic_t cookie);

     const char *
     magic_error(magic_t cookie);

     int
     magic_errno(magic_t cookie);

     const char *
     magic_file(magic_t cookie, const char *filename);

     const char *
     magic_buffer(magic_t cookie, const void *buffer, size_t length);

     int
     magic_setflags(magic_t cookie, int flags);

     int
     magic_check(magic_t cookie, const char *filename);

     int
     magic_compile(magic_t cookie, const char *filename);

     int
     magic_load(magic_t cookie, const char *filename);

DESCRIPTION
     These functions operate on the magic database file which
     is described in magic(5).

     The function magic_open() creates a magic cookie pointer
     and returns it. It returns NULL if there was an error
     allocating the magic cookie. The flags argument specifies
     how the other magic functions should behave:

     MAGIC_NONE      No special handling.

     MAGIC_DEBUG     Print debugging messages to stderr.

     MAGIC_SYMLINK   If the file queried is a symlink, follow
                     it.

     MAGIC_COMPRESS  If the file is compressed, unpack it and
                     look at the contents.

     MAGIC_DEVICES   If the file is a block or character spe-
                     cial device, then open the device and try
                     to look in its contents.

     MAGIC_MIME_TYPE
                     Return a MIME type string, instead of a
                     textual description.

     MAGIC_MIME_ENCODING
                     Return a MIME encoding, instead of a tex-
                     tual description.

     MAGIC_CONTINUE  Return all matches, not just the first.

     MAGIC_CHECK     Check the magic database for consistency
                     and print warnings to stderr.

     MAGIC_PRESERVE_ATIME
                     On systems that support utime(2) or
                     utimes(2), attempt to preserve the access
                     time of files analyzed.

     MAGIC_RAW       Don't translate unprintable characters to
                     a \ooo octal representation.

     MAGIC_ERROR     Treat operating system errors while trying
                     to open files and follow symlinks as real
                     errors, instead of printing them in the
                     magic buffer.

     MAGIC_NO_CHECK_APPTYPE
                     Check for EMX application type (only on
                     EMX).

     MAGIC_NO_CHECK_ASCII
                     Check for various types of ascii files.

     MAGIC_NO_CHECK_COMPRESS
                     Don't look for, or inside compressed
                     files.

     MAGIC_NO_CHECK_ELF
                     Don't print elf details.

     MAGIC_NO_CHECK_FORTRAN
                     Don't look for fortran sequences inside
                     ascii files.

     MAGIC_NO_CHECK_SOFT
                     Don't consult magic files.

     MAGIC_NO_CHECK_TAR
                     Don't examine tar files.

     MAGIC_NO_CHECK_TOKENS
                     Don't look for known tokens inside ascii
                     files.

     MAGIC_NO_CHECK_TROFF
                     Don't look for troff sequences inside
                     ascii files.

     The magic_close() function closes the magic(5) database
     and deallocates any resources used.

     The magic_error() function returns a textual explanation
     of the last error, or NULL if there was no error.

     The magic_errno() function returns the last operating sys-
     tem error number (errno(2)) that was encountered by a sys-
     tem call.

     The magic_file() function returns a textual description of
     the contents of the filename argument, or NULL if an error
     occurred.  If the filename is NULL, then stdin is used.

     The magic_buffer() function returns a textual description
     of the contents of the buffer argument with length bytes
     size.

     The magic_setflags() function sets the flags described
     above. Note that using both MIME flags together can also
     return extra information on the charset.

     The magic_check() function can be used to check the valid-
     ity of entries in the colon separated database files
     passed in as filename, or NULL for the default database.
     It returns 0 on success and -1 on failure.

     The magic_compile() function can be used to compile the
     the colon separated list of database files passed in as
     filename, or NULL for the default database. It returns 0
     on success and -1 on failure. The compiled files created
     are named from the basename(1) of each file argument with
     ``.mgc'' appended to it.

     The magic_load() function must be used to load the the
     colon separated list of database files passed in as
     filename, or NULL for the default database file before any
     magic queries can performed.

     The default database file is named by the MAGIC environ-
     ment variable.  If that variable is not set, the default
     database file name is c:/progra~1/file/share/misc/magic.
     magic_load() adds ``.mgc'' to the database filename as
     appropriate.

RETURN VALUES
     The function magic_open() returns a magic cookie on suc-
     cess and NULL on failure setting errno to an appropriate
     value. It will set errno to EINVAL if an unsupported value
     for flags was given.  The magic_load(), magic_compile(),
     and magic_check() functions return 0 on success and -1 on
     failure.  The magic_file(), and magic_buffer() functions
     return a string on success and NULL on failure. The
     magic_error() function returns a textual description of
     the errors of the above functions, or NULL if there was no
     error.  Finally, magic_setflags() returns -1 on systems
     that don't support utime(2), or utimes(2) when
     MAGIC_PRESERVE_ATIME is set.

FILES
     c:/progra~1/file/share/misc/magic      The non-compiled
                                            default magic data-
                                            base.
     c:/progra~1/file/share/misc/magic.mgc  The compiled
                                            default magic data-
                                            base.

SEE ALSO
     file(1), magic(5)

AUTHORS
     Måns Rullgård Initial libmagic implementation, and config-
     uration.  Christos Zoulas API cleanup, error code and
     allocation handling.

BSD                             October 6, 2008                            BSD
