1 files changed, 81 insertions, 0 deletions
diff --git a/apps/nshlib/nsh_fscmds.c b/apps/nshlib/nsh_fscmds.c
index f47dca896..83717e416 100644
--- a/apps/nshlib/nsh_fscmds.c
+++ b/apps/nshlib/nsh_fscmds.c
@@ -1232,3 +1232,84 @@ int cmd_sh(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
 }
 #endif
 #endif
+
+
+#if CONFIG_NFILE_DESCRIPTORS > 0
+#ifndef CONFIG_NSH_DISABLE_CMP
+int cmd_cmp(FAR struct nsh_vtbl_s *vtbl, int argc, char **argv)
+{
+  char *path1 = NULL;
+  char *path2 = NULL;
+  int fd1 = -1, fd2 = -1;
+  int ret = ERROR;
+  unsigned total_read = 0;
+
+  /* Get the full path to the two files */
+
+  path1 = nsh_getfullpath(vtbl, argv[1]);
+  if (!path1)
+    {
+      goto errout;
+    }
+
+  path2 = nsh_getfullpath(vtbl, argv[2]);
+  if (!path2)
+    {
+      goto errout;
+    }
+
+  /* Open the files for reading */
+  fd1 = open(path1, O_RDONLY);
+  if (fd1 < 0)
+    {
+      nsh_output(vtbl, g_fmtcmdfailed, argv[0], "open", NSH_ERRNO);
+      goto errout;
+    }
+
+  fd2 = open(path2, O_RDONLY);
+  if (fd2 < 0)
+    {
+      nsh_output(vtbl, g_fmtcmdfailed, argv[0], "open", NSH_ERRNO);
+      goto errout;
+    }
+
+  for (;;)
+    {
+      char buf1[128];
+      char buf2[128];
+
+      int nbytesread1 = read(fd1, buf1, sizeof(buf1));
+      int nbytesread2 = read(fd2, buf2, sizeof(buf2));
+
+      if (nbytesread1 < 0)
+          {
+	      nsh_output(vtbl, g_fmtcmdfailed, argv[0], "read", NSH_ERRNO);
+	      goto errout;
+	  }
+
+      if (nbytesread2 < 0)
+          {
+	      nsh_output(vtbl, g_fmtcmdfailed, argv[0], "read", NSH_ERRNO);
+	      goto errout;
+	  }
+
+      total_read += nbytesread1>nbytesread2?nbytesread2:nbytesread1;
+
+      if (nbytesread1 != nbytesread2 || memcmp(buf1, buf2, nbytesread1) != 0)
+          {
+	      nsh_output(vtbl, "files differ: byte %u\n", total_read);
+              goto errout;
+          }
+
+      if (nbytesread1 < sizeof(buf1)) break;
+    }
+
+  ret = OK;
+
+errout:
+  if (fd1 != -1) close(fd1);
+  if (fd2 != -1) close(fd2);
+  return ret;
+}
+#endif
+#endif