termemu: respect $SHELL and exec argv if given

Signed-off-by: John Hood <cgull@glup.org>

src/examples/termemu.cc

@@ -72,7 +72,7 @@ const size_t buf_size = 16384;
 
 static void emulate_terminal( int fd );
 
-int main( void )
+int main( int argc, char *argv[] )
 {
   int master;
   struct termios saved_termios, raw_termios, child_termios;
@@ -116,19 +116,26 @@ int main( void )
       exit( 1 );
     }
 
+    char *my_argv[ 2 ];
+
+    if ( argc > 1 ) {
+      argv++;
+    } else {
       /* get shell name */
+      my_argv[ 0 ] = getenv( "SHELL" );
+      if ( my_argv[ 0 ] == NULL ) {
 	struct passwd *pw = getpwuid( geteuid() );
 	if ( pw == NULL ) {
 	  perror( "getpwuid" );
 	  exit( 1 );
 	}
-
-    char *my_argv[ 2 ];
 	my_argv[ 0 ] = strdup( pw->pw_shell );
+      }
       assert( my_argv[ 0 ] );
       my_argv[ 1 ] = NULL;
-
+      argv = my_argv;
-    if ( execv( pw->pw_shell, my_argv ) < 0 ) {
+    }
+    if ( execvp( argv[ 0 ], argv ) < 0 ) {
       perror( "execve" );
       exit( 1 );
     }