From a07310d3cdb876ee6b3faaf01214168fbe5d2949 Mon Sep 17 00:00:00 2001
From: Giovanni Di Sirio <gdisirio@gmail.com>
Date: Sun, 5 Dec 2021 12:46:08 +0000
Subject: [PATCH] Added a simple "cat" command. Fixed VFS overlay driver file
 open.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@15203 27425a3e-05d8-49a3-a47f-9c15f0e5edd8
---
 os/various/shell/shell_cmd.c        | 21 +++++++++++----------
 os/vfs/drivers/overlay/drvoverlay.c | 25 +++++++++++++++++++------
 2 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/os/various/shell/shell_cmd.c b/os/various/shell/shell_cmd.c
index 9cd180165..910ee771e 100644
--- a/os/various/shell/shell_cmd.c
+++ b/os/various/shell/shell_cmd.c
@@ -238,7 +238,7 @@ static void scan_nodes(BaseSequentialStream *chp,
   msg_t res;
   vfs_directory_node_c *dirp;
 
-  chprintf(chp, "%s\r\n", path);
+  chprintf(chp, "%s" SHELL_NEWLINE_STR, path);
   res = vfsOpenDirectory(path, &dirp);
   if (res == VFS_RET_SUCCESS) {
     size_t i = strlen(path);
@@ -258,7 +258,7 @@ static void scan_nodes(BaseSequentialStream *chp,
         path[i] = '\0';
       }
       else {
-        chprintf(chp, "%s%s\r\n", path, fn);
+        chprintf(chp, "%s%s" SHELL_NEWLINE_STR, path, fn);
       }
     }
 
@@ -273,7 +273,7 @@ static void cmd_tree(BaseSequentialStream *chp, int argc, char *argv[]) {
   (void)argv;
 
   if (argc > 0) {
-    chprintf(chp, "Usage: tree\r\n");
+    chprintf(chp, "Usage: tree" SHELL_NEWLINE_STR);
     return;
   }
 
@@ -281,7 +281,7 @@ static void cmd_tree(BaseSequentialStream *chp, int argc, char *argv[]) {
     pathbuf = (char *)chHeapAlloc(NULL, 1024);
     nip = (vfs_node_info_t *)chHeapAlloc(NULL, 1024);
     if ((pathbuf == NULL) || (nip == NULL)) {
-      chprintf(chp, "Out of memory\r\n");
+      chprintf(chp, "Out of memory" SHELL_NEWLINE_STR);
      break;
     }
 
@@ -303,7 +303,7 @@ static void cmd_cat(BaseSequentialStream *chp, int argc, char *argv[]) {
   char *buf = NULL;
 
   if (argc != 1) {
-    chprintf(chp, "Usage: cat <filename>\r\n");
+    chprintf(chp, "Usage: cat <filename>" SHELL_NEWLINE_STR);
     return;
   }
 
@@ -312,19 +312,20 @@ static void cmd_cat(BaseSequentialStream *chp, int argc, char *argv[]) {
 
     buf= (char *)chHeapAlloc(NULL, 2048);
     if (buf == NULL) {
-      chprintf(chp, "Out of memory\r\n");
+      chprintf(chp, "Out of memory" SHELL_NEWLINE_STR);
      break;
     }
 
-    fd = open(argv[1], O_RDONLY);
+    fd = open(argv[0], O_RDONLY);
     if(fd == -1) {
-      chprintf(chp, "Cannot open file\r\n");
+      chprintf(chp, "Cannot open file" SHELL_NEWLINE_STR);
       break;
     }
 
-    while ((n = read(fd, buf, sizeof (buf))) > 0) {
-      chprintf(chp, "%s", buf);
+    while ((n = read(fd, buf, sizeof (2048))) > 0) {
+      streamWrite(chp, (const uint8_t *)buf, n);
     }
+    chprintf(chp, SHELL_NEWLINE_STR);
 
     (void) close(fd);
   }
diff --git a/os/vfs/drivers/overlay/drvoverlay.c b/os/vfs/drivers/overlay/drvoverlay.c
index eb4098508..bc42a120c 100644
--- a/os/vfs/drivers/overlay/drvoverlay.c
+++ b/os/vfs/drivers/overlay/drvoverlay.c
@@ -170,13 +170,14 @@ static msg_t drv_open_file(void *instance,
                            int oflag,
                            vfs_file_node_c **vfnpp) {
   vfs_overlay_driver_c *drvp = (vfs_overlay_driver_c *)instance;
+  const char *scanpath = path;
   msg_t err;
 
   do {
-    err = vfs_parse_match_separator(&path);
+    err = vfs_parse_match_separator(&scanpath);
     VFS_BREAK_ON_ERROR(err);
 
-    if (*path == '\0') {
+    if (*scanpath == '\0') {
       (void)instance;
 
       /* Always not found, there are no files in the root.*/
@@ -185,11 +186,23 @@ static msg_t drv_open_file(void *instance,
     else {
       vfs_driver_c *dp;
 
-      /* Delegating node creation to a registered driver.*/
-      err = match_driver(drvp, &path, &dp);
-      VFS_BREAK_ON_ERROR(err);
+      /* Searching for a match among registered overlays.*/
+      err = match_driver(drvp, &scanpath, &dp);
+      if (err == VFS_RET_SUCCESS) {
+        /* Delegating node creation to a registered driver.*/
+        err = dp->vmt->open_file((void *)dp, scanpath, oflag, vfnpp);
+      }
+      else {
+        /* No matching overlay, the whole path is passed to the overlaid
+           driver, if defined, else returning the previous error.*/
+        if (drvp->overlaid_drv != NULL) {
+          err = drvp->overlaid_drv->vmt->open_file((void *)drvp->overlaid_drv,
+                                                   path,
+                                                   oflag,
+                                                   vfnpp);
+        }
+      }
 
-      err = dp->vmt->open_file((void *)dp, path, oflag, vfnpp);
     }
   }
   while (false);