Package: file
Version: 4.17-4
Followup-For: Bug #38542
I am having problems with these rules too, and there seems to be no
way to turn them off. I can see how they might be useful e.g. in code
analysis, but for other uses (e.g. determining MIME type for serving
files from a web application) they are a positive nuisance: all sorts
of text-ish files end up being identified as program source. Of
course, I want REAL program sources (ending in the correct suffixes,
normally) to be identified as such, but equally non-suffixed files
that aren't text (e.g. scripts) should also be correctly identified,
so I can't rely on suffixes alone.
I attach a (tested!) patch (code and docs!) to add a new option
--no-ascmagic/-A.
-- System Information:
Debian Release: testing/unstable
APT prefers testing
APT policy: (500, 'testing')
Architecture: i386 (i686)
Shell: /bin/sh linked to /bin/bash
Kernel: Linux 2.6.16
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Versions of packages file depends on:
ii libc6 2.3.6.ds1-4 GNU C Library: Shared libraries
ii libmagic1 4.17-4 File type determination library us
file recommends no packages.
-- no debconf information
diff -Nur file-4.17/doc/file.man file-4.17-opt_ascmagic/doc/file.man
--- file-4.17/doc/file.man 2006-10-23 19:39:10.000000000 +0100
+++ file-4.17-opt_ascmagic/doc/file.man 2006-10-23 20:18:03.000000000 +0100
@@ -6,7 +6,7 @@
.SH SYNOPSIS
.B file
[
-.B \-bchikLnNprsvz
+.B \-bchiAkLnNprsvz
]
[
.B \-f
@@ -194,6 +194,11 @@
.I POSIXLY_CORRECT
is not defined.
.TP 8
+.B "\-A, \-\-no-ascmagic"
+Causes built-in rules to guess certain programming language source
+types from their content to be skipped. These rules can cause problems
+by giving false positives on plain text files.
+.TP 8
.B "\-i, \-\-mime"
Causes the file command to output mime type strings rather than the more
traditional human readable ones. Thus it may say
diff -Nur file-4.17/src/file.c file-4.17-opt_ascmagic/src/file.c
--- file-4.17/src/file.c 2006-10-23 19:39:10.000000000 +0100
+++ file-4.17-opt_ascmagic/src/file.c 2006-10-23 20:22:10.000000000 +0100
@@ -126,7 +126,7 @@
int flags = 0;
char *home, *usermagic;
struct stat sb;
-#define OPTSTRING "bcCdf:F:hikLm:nNprsvz"
+#define OPTSTRING "bcCdf:F:hiAkLm:nNprsvz"
#ifdef HAVE_GETOPT_LONG
int longindex;
private struct option long_options[] =
@@ -139,6 +139,7 @@
{"files-from", 1, 0, 'f'},
{"separator", 1, 0, 'F'},
{"mime", 0, 0, 'i'},
+ {"no-ascmagic", 0, 0, 'A'},
{"keep-going", 0, 0, 'k'},
#ifdef S_IFLNK
{"dereference", 0, 0, 'L'},
@@ -229,6 +230,9 @@
case 'i':
flags |= MAGIC_MIME;
break;
+ case 'A':
+ flags |= MAGIC_NOASCMAGIC;
+ break;
case 'k':
flags |= MAGIC_CONTINUE;
break;
diff -Nur file-4.17/src/funcs.c file-4.17-opt_ascmagic/src/funcs.c
--- file-4.17/src/funcs.c 2006-03-02 22:10:26.000000000 +0000
+++ file-4.17-opt_ascmagic/src/funcs.c 2006-10-23 20:10:03.000000000 +0100
@@ -128,7 +128,7 @@
/* try tests in /etc/magic (or surrogate magic file) */
if ((m = file_softmagic(ms, buf, nb)) == 0) {
/* try known keywords, check whether it is ASCII */
- if ((m = file_ascmagic(ms, buf, nb)) == 0) {
+ if (ms->flags & MAGIC_NOASCMAGIC || (m = file_ascmagic(ms, buf,
nb)) == 0) {
/* abandon hope, all ye who remain here */
if (file_printf(ms, ms->flags & MAGIC_MIME ?
(nb ? "application/octet-stream" :
diff -Nur file-4.17/src/magic.h file-4.17-opt_ascmagic/src/magic.h
--- file-4.17/src/magic.h 2004-09-25 16:20:29.000000000 +0100
+++ file-4.17-opt_ascmagic/src/magic.h 2006-10-23 20:10:59.000000000 +0100
@@ -40,6 +40,7 @@
#define MAGIC_PRESERVE_ATIME 0x080 /* Restore access time on exit
*/
#define MAGIC_RAW 0x100 /* Don't translate unprintable
chars */
#define MAGIC_ERROR 0x200 /* Handle ENOENT etc as real
errors */
+#define MAGIC_NOASCMAGIC 0x400 /* Don't use ascmagic rules */
#ifdef __cplusplus
extern "C" {
