FreeBSD Man Pages

libmagic(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 con-
		     tents.

     MAGIC_CHECK     Check the magic database for consistency and print warn-
		     ings 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.

     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 system error number
     ( errno(3)) that was encountered by a system 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.

     The magic_check() function can be used to check the validity 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 sepa-
     rated 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 environment variable.  If
     that variable is not set, the default database file name is
     /usr/share/misc/magic.

     magic_load() adds ".mime" and/or ".mgc" to the database filename as
     appropriate.

RETURN VALUES

     The function magic_open() returns a magic cookie on success and NULL on
     failure setting errno to an appropriate value. It will set errno to EIN-
     VAL if an unsupported value for flags was given.  The magic_load(),
     magic_compile(), and magic_check() functions return 0 on success and -1
				     base.
     /usr/share/misc/magic.mime.mgc  The compiled default magic mime database.
     /usr/share/misc/magic	     The non-compiled default magic database.
     /usr/share/misc/magic.mgc	     The compiled default magic database.

SEE ALSO

     file(1), magic(5)

AUTHORS

     Mans Rullgard Initial libmagic implementation, and configuration.	Chris-
     tos Zoulas API cleanup, error code and allocation handling.

FreeBSD 5.4			March 22, 2003			   FreeBSD 5.4

SPONSORED LINKS