sys/shell: terminate shell on Ctrl-D

Ctrl-D was not caught in a special case so it was interpreted as
a standard character. Handle it now the same way like EOF and
terminate the shell instance.

sys/shell/shell.c

@@ -38,7 +38,8 @@
 #include "shell.h"
 #include "shell_commands.h"
 
-#define ETX '\x03'  /** ASCII "End-of-Text", or ctrl-C */
+#define ETX '\x03'  /** ASCII "End-of-Text", or Ctrl-C */
+#define EOT '\x04'  /** ASCII "End-of-Transmission", or Ctrl-D */
 #define BS  '\x08'  /** ASCII "Backspace" */
 #define DEL '\x7f'  /** ASCII "Delete" */
 
@@ -411,6 +412,9 @@ static int readline(char *buf, size_t size)
 
         switch (c) {
 
+            case EOT:
+                /* Ctrl-D terminates the current shell instance. */
+                /* fall-thru */
             case EOF:
                 return EOF;
 

tests/shell/main.c

@@ -97,13 +97,18 @@ static const shell_command_t shell_commands[] = {
 
 int main(void)
 {
-
     printf("test_shell.\n");
 
     /* define buffer to be used by the shell */
     char line_buf[SHELL_DEFAULT_BUFSIZE];
 
     /* define own shell commands */
+    shell_run_once(shell_commands, line_buf, SHELL_DEFAULT_BUFSIZE);
+
+    puts("shell exited");
+
+    /* Restart the shell after the previous one exits, so that we can test
+     * Ctrl-D exit */
     shell_run(shell_commands, line_buf, SHELL_DEFAULT_BUFSIZE);
 
     /* or use only system shell commands */

tests/shell/tests/01-run.py

@@ -182,6 +182,19 @@ def check_erase_long_line(child, longline):
         child.expect_exact('"echo"')
 
 
+def check_control_d(child):
+    # The current shell instance was initiated by shell_run_once(). The shell will exit.
+    child.sendline(CONTROL_D)
+    child.expect_exact('shell exited')
+
+    # The current shell instance was initiated by shell_run(). The shell will respawn
+    # automatically except on native. On native, RIOT is shut down completely,
+    # therefore exclude this part.
+    if BOARD != 'native':
+        child.sendline(CONTROL_D)
+        child.expect_exact(PROMPT)
+
+
 def testfunc(child):
     # avoid sending an extra empty line on native.
     if BOARD == 'native':
@@ -199,6 +212,8 @@ def testfunc(child):
 
     check_erase_long_line(child, longline)
 
+    check_control_d(child)
+
     # loop other defined commands and expected output
     for cmd, expected in CMDS:
         check_cmd(child, cmd, expected)