ui_plain: automatically lookup mimetype when mimetype-file is set

For sites that do not want to configure mime types by hand but
still want the correct mime type for 'plain' blobs, configuring
a mime type file is made possible. This is handy since such a
file is normally already provided (at least on Linux systems).

Also, this reflects the gitweb option '$mimetypes_file'

Signed-off-by: Ferry Huberts <ferry.huberts@pelagic.nl>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

4 files changed, 65 insertions, 1 deletions

diff --git a/cgit.c b/cgit.c
index b7807ad..abb698b 100644
--- a/cgit.c
+++ b/cgit.c
@@ -236,6 +236,8 @@ void config_cb(const char *name, const char *value)
                 ctx.cfg.ssdiff = atoi(value);
         else if (!strcmp(name, "agefile"))
                 ctx.cfg.agefile = xstrdup(value);
+        else if (!strcmp(name, "mimetype-file"))
+                ctx.cfg.mimetype_file = xstrdup(value);
         else if (!strcmp(name, "renamelimit"))
                 ctx.cfg.renamelimit = atoi(value);
         else if (!strcmp(name, "remove-suffix"))
diff --git a/cgit.h b/cgit.h
index bad66f0..db24941 100644
--- a/cgit.h
+++ b/cgit.h
@@ -175,6 +175,7 @@ struct cgit_config {
         char *index_info;
         char *logo;
         char *logo_link;
+        char *mimetype_file;
         char *module_link;
         char *project_list;
         char *readme;
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index 4721c1e..22a0dc3 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -226,6 +226,17 @@ mimetype.<ext>::
         Set the mimetype for the specified filename extension. This is used
         by the `plain` command when returning blob content.
 
+mimetype-file::
+        Specifies the file to use for automatic mimetype lookup. If specified
+        then this field is used as a fallback when no "mimetype.<ext>" match is
+        found. If unspecified then no such lookup is performed. The typical file
+        to use on a Linux system is /etc/mime.types. Default value: none. See
+        also: "mimetype.<ext>". The format of the file must comply to:
+        - a comment line is an empty line or a line starting with a hash (#),
+          optionally preceded by whitespace
+        - a non-comment line starts with the mimetype (like image/png), followed
+          by one or more file extensions (like jpg), all separated by whitespace
+
 module-link::
         Text which will be used as the formatstring for a hyperlink when a
         submodule is printed in a directory listing. The arguments for the
diff --git a/ui-plain.c b/ui-plain.c
index 733db4d..7fecc32 100644
--- a/ui-plain.c
+++ b/ui-plain.c
@@ -6,6 +6,7 @@
  *   (see COPYING for full license text)
  */
 
+#include <stdio.h>
 #include "cgit.h"
 #include "html.h"
 #include "ui-shared.h"
@@ -13,12 +14,53 @@
 int match_baselen;
 int match;
 
+static char *get_mimetype_from_file(const char *filename, const char *ext)
+{
+        static const char *delimiters;
+        char *result;
+        FILE *fd;
+        char line[1024];
+        char *mimetype;
+        char *token;
+
+        if (!filename)
+                return NULL;
+
+        fd = fopen(filename, "r");
+        if (!fd)
+                return NULL;
+
+        delimiters = " \t\r\n";
+        result = NULL;
+
+        /* loop over all lines in the file */
+        while (!result && fgets(line, sizeof(line), fd)) {
+                mimetype = strtok(line, delimiters);
+
+                /* skip empty lines and comment lines */
+                if (!mimetype || (mimetype[0] == '#'))
+                        continue;
+
+                /* loop over all extensions of mimetype */
+                while ((token = strtok(NULL, delimiters))) {
+                        if (!strcasecmp(ext, token)) {
+                                result = xstrdup(mimetype);
+                                break;
+                        }
+                }
+        }
+        fclose(fd);
+
+        return result;
+}
+
 static void print_object(const unsigned char *sha1, const char *path)
 {
         enum object_type type;
         char *buf, *ext;
         unsigned long size;
         struct string_list_item *mime;
+        int freemime;
 
         type = sha1_object_info(sha1, &size);
         if (type == OBJ_BAD) {
@@ -33,10 +75,16 @@ static void print_object(const unsigned char *sha1, const char *path)
         }
         ctx.page.mimetype = NULL;
         ext = strrchr(path, '.');
+        freemime = 0;
         if (ext && *(++ext)) {
                 mime = string_list_lookup(&ctx.cfg.mimetypes, ext);
-                if (mime)
+                if (mime) {
                         ctx.page.mimetype = (char *)mime->util;
+                } else {
+                        ctx.page.mimetype = get_mimetype_from_file(ctx.cfg.mimetype_file, ext);
+                        if (ctx.page.mimetype)
+                                freemime = 1;
+                }
         }
         if (!ctx.page.mimetype) {
                 if (buffer_is_binary(buf, size))
@@ -50,6 +98,8 @@ static void print_object(const unsigned char *sha1, const char *path)
         cgit_print_http_headers(&ctx);
         html_raw(buf, size);
         match = 1;
+        if (freemime)
+                free(ctx.page.mimetype);
 }
 
 static char *buildpath(const char *base, int baselen, const char *path)