From 4104019e1cf8895dd6128cff90952be2e4ec90ee Mon Sep 17 00:00:00 2001
From: Marco Casaroli <marco.casaroli@gmail.com>
Date: Tue, 6 Aug 2024 23:52:34 +0200
Subject: [PATCH] feat(nsh): add console read

This allows programs such as `cat` to read from the console (that could be redirected).
---
 nshlib/nsh_console.c | 29 +++++++++++++++++++++++++++++
 nshlib/nsh_console.h |  3 +++
 2 files changed, 32 insertions(+)

diff --git a/nshlib/nsh_console.c b/nshlib/nsh_console.c
index 444a65421..6b19ef3e1 100644
--- a/nshlib/nsh_console.c
+++ b/nshlib/nsh_console.c
@@ -139,6 +139,34 @@ static ssize_t nsh_consolewrite(FAR struct nsh_vtbl_s *vtbl,
   return ret;
 }
 
+/****************************************************************************
+ * Name: nsh_consoleread
+ *
+ * Description:
+ *   read a buffer to the remote shell window.
+ *
+ *   Currently only used by cat.
+ *
+ ****************************************************************************/
+
+static ssize_t nsh_consoleread(FAR struct nsh_vtbl_s *vtbl,
+                                FAR void *buffer, size_t nbytes)
+{
+  FAR struct console_stdio_s *pstate = (FAR struct console_stdio_s *)vtbl;
+  ssize_t ret;
+
+  /* Read the data to the output stream */
+
+  ret = read(INFD(pstate), buffer, nbytes);
+  if (ret < 0)
+    {
+      _err("ERROR: [%d] Failed to read buffer: %d\n",
+          INFD(pstate), errno);
+    }
+
+  return ret;
+}
+
 /****************************************************************************
  * Name: nsh_consolewrite
  *
@@ -380,6 +408,7 @@ FAR struct console_stdio_s *nsh_newconsole(bool isctty)
 #endif
       pstate->cn_vtbl.release     = nsh_consolerelease;
       pstate->cn_vtbl.write       = nsh_consolewrite;
+      pstate->cn_vtbl.read        = nsh_consoleread;
       pstate->cn_vtbl.ioctl       = nsh_consoleioctl;
       pstate->cn_vtbl.output      = nsh_consoleoutput;
 #ifndef CONFIG_NSH_DISABLE_ERROR_PRINT
diff --git a/nshlib/nsh_console.h b/nshlib/nsh_console.h
index 7f950460a..a03ea664a 100644
--- a/nshlib/nsh_console.h
+++ b/nshlib/nsh_console.h
@@ -44,6 +44,7 @@
 #define nsh_clone(v)            (v)->clone(v)
 #define nsh_release(v)          (v)->release(v)
 #define nsh_write(v,b,n)        (v)->write(v,b,n)
+#define nsh_read(v,b,n)         (v)->read(v,b,n)
 #define nsh_ioctl(v,c,a)        (v)->ioctl(v,c,a)
 #define nsh_linebuffer(v)       (v)->linebuffer(v)
 #define nsh_redirect(v,fi,fo,s) (v)->redirect(v,fi,fo,s)
@@ -113,6 +114,8 @@ struct nsh_vtbl_s
   void (*release)(FAR struct nsh_vtbl_s *vtbl);
   ssize_t (*write)(FAR struct nsh_vtbl_s *vtbl, FAR const void *buffer,
                    size_t nbytes);
+  ssize_t (*read)(FAR struct nsh_vtbl_s *vtbl, FAR void *buffer,
+                   size_t nbytes);
   int (*ioctl)(FAR struct nsh_vtbl_s *vtbl, int cmd, unsigned long arg);
 #ifndef CONFIG_NSH_DISABLE_ERROR_PRINT
   int (*error)(FAR struct nsh_vtbl_s *vtbl, FAR const char *fmt, ...)