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

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

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=42766b3db2c895be02404dc89995412e841f05b7

commit 42766b3db2c895be02404dc89995412e841f05b7
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Tue Mar 24 15:47:13 2020 -0300

    support/shell-container.c: Add builtin kill
    
    No options supported.
    
    Reviewed-by: DJ Delorie <dj@redhat.com>
    
    (cherry picked from commit 1c17100c43c0913ec94f3bcc966bf3792236c690)

Diff:
---
 support/shell-container.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/support/shell-container.c b/support/shell-container.c
index 99a0ff7ca5..51b01dce0d 100644
--- a/support/shell-container.c
+++ b/support/shell-container.c
@@ -147,6 +147,25 @@ exit_func (char **argv)
   return 0;
 }
 
+/* Emulate the "/bin/kill" command.  Options are ignored.  */
+static int
+kill_func (char **argv)
+{
+  int signum = SIGTERM;
+  int i;
+
+  for (i = 0; argv[i]; i++)
+    {
+      pid_t pid;
+      if (strcmp (argv[i], "$$") == 0)
+	pid = getpid ();
+      else
+	pid = atoi (argv[i]);
+      kill (pid, signum);
+    }
+  return 0;
+}
+
 /* This is a list of all the built-in commands we understand.  */
 static struct {
   const char *name;
@@ -156,6 +175,7 @@ static struct {
   { "echo", echo_func },
   { "cp", copy_func },
   { "exit", exit_func },
+  { "kill", kill_func },
   { NULL, NULL }
 };
 
@@ -264,6 +284,11 @@ run_command_array (char **argv)
       if (rv)
 	exit (rv);
     }
+  else if (WIFSIGNALED (status))
+    {
+      int sig = WTERMSIG (status);
+      raise (sig);
+    }
   else
     exit (1);
 }