[glibc/ibm/2.30/master] support/shell-container.c: Add builtin exit

[Tulio Magno Quites Machado Filho <tuliom@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=946ee0281a5a409c6e4af08fabcde9b03cf1624d

commit 946ee0281a5a409c6e4af08fabcde9b03cf1624d
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Tue Mar 24 15:40:36 2020 -0300

    support/shell-container.c: Add builtin exit
    
    Reviewed-by: DJ Delorie <dj@redhat.com>
    
    (cherry picked from commit 5a5a3a3234bc220a5192d620e0cbc5360da46f14)

Diff:
---
 support/shell-container.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/support/shell-container.c b/support/shell-container.c
index abf40e4167..99a0ff7ca5 100644
--- a/support/shell-container.c
+++ b/support/shell-container.c
@@ -135,6 +135,18 @@ copy_func (char **argv)
 
 }
 
+/* Emulate the 'exit' builtin.  The exit value is optional.  */
+static int
+exit_func (char **argv)
+{
+  int exit_val = 0;
+
+  if (argv[0] != 0)
+    exit_val = atoi (argv[0]) & 0xff;
+  exit (exit_val);
+  return 0;
+}
+
 /* This is a list of all the built-in commands we understand.  */
 static struct {
   const char *name;
@@ -143,6 +155,7 @@ static struct {
   { "true", true_func },
   { "echo", echo_func },
   { "cp", copy_func },
+  { "exit", exit_func },
   { NULL, NULL }
 };