More splits from "tuxpaint.c":

+ "debug.h": Defines whether debugging printf() calls should be enabled.
  + "dirwalk.c/h": Callback functions for recursive directory traversal.
  + "fonts.c/h": Font loading/grouping/discarding variables and functions.
  + "get_fname.c/h": Functions for constructing preferred file paths.

src/get_fname.c

@@ -0,0 +1,99 @@
+/*
+  get_fname.c
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "get_fname.h"
+#include "debug.h"
+
+char * savedir;
+
+
+/* The filename for the current image: */
+
+char * get_fname(const char * const name)
+{
+  char f[512];
+  const char * tux_settings_dir;
+
+
+  /* Where is the user's data directory?
+     This is where their saved files are stored,
+     local fonts, brushes and stamps can be found,
+     and where the "current_id.txt" file is saved */
+
+#ifdef WIN32
+  /* Windows predefines "savedir" as:
+     "C:\Documents and Settings\%USERNAME%\Application Data\TuxPaint"
+     though it may get overridden with "--savedir" option */
+
+  snprintf(f, sizeof(f), "%s/%s", savedir, name);
+
+#elif __BEOS__
+  /* BeOS similarly predefines "savedir" as "./userdata"... */
+
+  if (*name == '\0')
+    strcpy(f, savedir);
+  else
+    snprintf(f, sizeof(f), "%s/%s", savedir, name);
+
+#elif __APPLE__
+  /* Macintosh: It's under ~/Library/Application Support/TuxPaint */
+
+  tux_settings_dir = "Library/Application Support/TuxPaint";
+#else
+  /* Linux & Unix: It's under ~/.tuxpaint */
+
+  tux_settings_dir = ".tuxpaint";
+#endif
+
+
+  /* Put together home directory path + settings directory + filename... */
+
+  if (savedir == NULL)
+    {
+      /* Save directory not overridden: */
+
+      if (getenv("HOME") != NULL)
+        {
+          if (*name == '\0')
+            {
+              /* (Some mkdir()'s don't like trailing slashes) */
+
+              snprintf(f, sizeof(f), "%s/%s", getenv("HOME"), tux_settings_dir);
+            }
+          else
+            {
+              snprintf(f, sizeof(f), "%s/%s/%s",
+                       getenv("HOME"), tux_settings_dir, name);
+            }
+        }
+      else
+        {
+          /* WOAH!  Don't know where HOME directory is!  Last resort, use '.'! */
+
+          strcpy(f, name);
+        }
+    }
+  else
+    {
+      /* User had overridden save directory with "--savedir" option: */
+
+      if (*name != '\0')
+        {
+          /* (Some mkdir()'s don't like trailing slashes) */
+
+          snprintf(f, sizeof(f), "%s/%s", savedir, name);
+        }
+      else
+        {
+          snprintf(f, sizeof(f), "%s", savedir);
+        }
+    }
+
+  return strdup(f);
+}
+