Re: using libmagic in Emacs?

[Andreas Schwab]

address@hidden writes:

> diff --git a/configure.in b/configure.in
> index f4096db..cb74523 100644
> --- a/configure.in
> +++ b/configure.in
> @@ -137,6 +137,8 @@ OPTION_DEFAULT_ON([xft],[don't use XFT for anti aliased 
> fonts])
>  OPTION_DEFAULT_ON([libotf],[don't use libotf for OpenType font support])
>  OPTION_DEFAULT_ON([m17n-flt],[don't use m17n-flt for text shaping])
>  
> +OPTION_DEFAULT_ON([filemagic],[don't compile with filemagic support])

IMHO the option should be named libmagic, since that's how the library
is named.

> diff --git a/src/config.in b/src/config.in
> index 404e00b..c966a09 100644
> --- a/src/config.in
> +++ b/src/config.in
> @@ -262,6 +262,9 @@ along with GNU Emacs.  If not, see 
> <http://www.gnu.org/licenses/>.  */
>  /* Define to 1 if you have the gpm library (-lgpm). */
>  #undef HAVE_GPM
>  
> +/* Define to 1 if you have the filemagic library (-lmagic). */
> +#undef HAVE_LIBMAGIC
> +
>  /* Define to 1 if you have the `grantpt' function. */
>  #undef HAVE_GRANTPT
>  

This is generated by autoheader.

> diff --git a/src/fileio.c b/src/fileio.c
> index 3702d4c..375502e 100644
> --- a/src/fileio.c
> +++ b/src/fileio.c
> @@ -205,6 +205,10 @@ Lisp_Object Vdirectory_sep_char;
>  int write_region_inhibit_fsync;
>  #endif
>  
> +#ifdef HAVE_LIBMAGIC
> +#include <magic.h>
> +#endif
> +
>  /* Non-zero means call move-file-to-trash in Fdelete_file or
>     Fdelete_directory.  */
>  int delete_by_moving_to_trash;
> @@ -2997,6 +3001,45 @@ DEFUN ("unix-sync", Funix_sync, Sunix_sync, 0, 0, "",
>  
>  #endif /* HAVE_SYNC */
>  
> +#ifdef HAVE_LIBMAGIC
> +DEFUN ("file-magic-file", Ffile_magic_file, Sfile_magic_file, 1,1,0,
> +       doc: /* Return (MIME_TYPE MIME_ENCODING DESCRIPTION) for FILENAME.
> +Return nil on error. */)
> +  (filename)
> +     Lisp_Object filename;
> +{
> +  magic_t cookie=NULL;
> +  if (!STRINGP (filename)) goto libmagic_error;

Just use CHECK_STRING.

> +  char* f = SDATA (filename);
> +  char* rvs;

No C99 features yet.  Be careful with raw string pointers and GC.

> +  cookie = magic_open (MAGIC_NONE);
> +  magic_load (cookie,NULL); //load default database

if (cookie == NULL) ?

> +
> +  magic_setflags (cookie, MAGIC_MIME_TYPE);  
> +  rvs = magic_file (cookie, f);
> +  if (rvs == NULL) goto libmagic_error;

Use report_file_error, provided that magic_file sets errno appropriately.

> +  Lisp_Object file_freetext = make_specified_string (rvs, strlen(rvs), 
> strlen(rvs), NULL);    

Use build_string.

Andreas.

-- 
Andreas Schwab, address@hidden
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"And now for something completely different."