shell commands are really working now

1 files changed, 106 insertions, 3 deletions

diff --git a/plugins/shellexec/shellexec.c b/plugins/shellexec/shellexec.c
index 178add2e..f576ca9b 100644
--- a/plugins/shellexec/shellexec.c
+++ b/plugins/shellexec/shellexec.c
@@ -47,11 +47,114 @@ trim (char* s)
 }
 
 static int
+shell_quote (const char *source, char *dest)
+{
+    char *sp, *dp;
+
+    for (sp = source, dp = dest; *sp; sp++, dp++)
+    {
+        if (*sp == '\'')
+        {
+            strcpy (dp, "'\\''");
+            dp += 3;
+        }
+        else
+            *dp = *sp;
+    }
+    *dp = 0;
+}
+
+
+/*
+    format_shell_command function
+    Similarly to db_format_title formats track's string
+    and quotes all fields to make them safe for shell
+    
+    %a, %t, %b, %B, %C, %n, %N, %y, %g, %c, %r are handled. Use double-% to
+    skip field.
+
+
+    Example:
+
+    Format string:
+    echo %a - %t %%a - %%t
+
+    Output:
+    echo 'Blind Faith' - 'Can'\''t Find My Way Home' %a - %t
+*/
+static const char*
+format_shell_command (DB_playItem_t *it, const char *format)
+{
+    char *p;
+    const char *trailing = format;
+    const char *field;
+    char *res, *res_p;
+
+    res = res_p = malloc (65536); //FIXME: possible heap corruption
+
+    for (;;)
+    {
+        p = strchr (trailing, '%');
+        if (!p) break;
+
+        switch (*(p+1))
+        {
+            case 'a': field = "artist"; break;
+            case 't': field = "title"; break;
+            case 'b': field = "album"; break;
+            case 'B': field = "band"; break;
+            case 'C': field = "composer"; break;
+            case 'n': field = "track"; break;
+            case 'N': field = "numtracks"; break;
+            case 'y': field = "year"; break;
+            case 'g': field = "genre"; break;
+            case 'c': field = "comment"; break;
+            case 'r': field = "copyright"; break;
+            case 'f': break;
+            default: field = NULL;
+        }
+
+        if (field == NULL)
+        {
+            int l = ((*(p+1) == '%') ? 1 : 0);
+            trace ("field is null; p: %s; p+1: %s; l: %d; trailing: %s; res_p: %s\n", p, p+1, l, trailing, res_p);
+            strncpy (res_p, trailing, p-trailing+l);
+            res_p += (p-trailing+l);
+            trailing = p+l+1;
+            trace ("res: %s; trailing: %s\n", res, res_p, trailing);
+            continue;
+        }
+        else
+        {
+            const char *meta;
+            if (*(p+1) == 'f')
+                meta = it->fname;
+            else
+                meta = deadbeef->pl_find_meta (it, field);
+
+            char quoted [strlen (meta) * 4 + 1]; //Worst case is when all chars are single quote
+            shell_quote (meta, quoted);
+            
+            strncpy (res_p, trailing, p-trailing);
+            res_p += (p-trailing);
+            *res_p++ = '\'';
+            strcpy (res_p, quoted);
+            res_p += strlen (quoted);
+            *res_p++ = '\'';
+            trailing = p+2;
+        }
+    }
+    strcpy (res_p, trailing);
+    return res;
+}
+
+static int
 shx_callback (DB_playItem_t *it, void *data)
 {
-    char fmt[1024]; //FIXME: possible stack corruption
-    deadbeef->pl_format_title (it, -1, fmt, sizeof (fmt), -1, data);
-    printf ("%s\n", fmt);
+    const char *cmd = format_shell_command (it, data);
+    printf ("%s\n", cmd);
+    system (cmd);
+    free (cmd);
     return 0;
 }