exit built-in for sh

ed4c69d0 · Silas Boyd-Wickizer · 72873e7a · ed4c69d0
--- a/bin/sh.cc
+++ b/bin/sh.cc
@@ -164,6 +164,8 @@ main(void)
      if(chdir(buf+3) < 0)
        fprintf(2, "cannot cd %s\n", buf+3);
      continue;
+    } else if(!strcmp(buf, "exit\n") || !strcmp(buf, "exit\r")){
+      exit();
    }
    if(fork1() == 0)
      runcmd(parsecmd(buf));