1 files changed, 38 insertions, 0 deletions
diff --git a/fatfs/documents/res/app5.c b/fatfs/documents/res/app5.c
new file mode 100644
index 0000000..2739019
--- /dev/null
+++ b/fatfs/documents/res/app5.c
@@ -0,0 +1,38 @@
+/*----------------------------------------------------------------------/
+/ Test if the file is contiguous                                        /
+/----------------------------------------------------------------------*/
+
+FRESULT test_contiguous_file (
+    FIL* fp,    /* [IN]  Open file object to be checked */
+    int* cont   /* [OUT] 1:Contiguous, 0:Fragmented or zero-length */
+)
+{
+    DWORD clst, clsz, step;
+    FSIZE_t fsz;
+    FRESULT fr;
+
+
+    *cont = 0;
+    fr = f_rewind(fp);              /* Validates and prepares the file */
+    if (fr != FR_OK) return fr;
+
+#if FF_MAX_SS == FF_MIN_SS
+    clsz = (DWORD)fp->obj.fs->csize * FF_MAX_SS;    /* Cluster size */
+#else
+    clsz = (DWORD)fp->obj.fs->csize * fp->obj.fs->ssize;
+#endif
+    fsz = f_size(fp);
+    if (fsz > 0) {
+        clst = fp->obj.sclust - 1;  /* A cluster leading the first cluster for first test */
+        while (fsz) {
+            step = (fsz >= clsz) ? clsz : (DWORD)fsz;
+            fr = f_lseek(fp, f_tell(fp) + step);    /* Advances file pointer a cluster */
+            if (fr != FR_OK) return fr;
+            if (clst + 1 != fp->clust) break;       /* Is not the cluster next to previous one? */
+            clst = fp->clust; fsz -= step;          /* Get current cluster for next test */
+        }
+        if (fsz == 0) *cont = 1;    /* All done without fail? */
+    }
+
+    return FR_OK;
+}