Run sh commands specified on the host command line.

E.g. make RUN="avar on; ls; avar off; halt"

Run sh commands specified on the host command line.
a0fa7973 · Silas Boyd-Wickizer · dca2a740 · a0fa7973 · a0fa7973 · a0fa7973
--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,7 @@ QEMUSRC    ?= ../mtrace
 MTRACE	   ?= $(QEMU)
 HW	   ?= qemu
 EXCEPTIONS ?= y
+RUN	   ?= $(empty)
 O  	   = o.$(HW)

 ifdef USE_CLANG
@@ -97,7 +98,8 @@ $(O)/fs.img: $(O)/tools/mkfs README $(UPROGS)
 ##
 QEMUOPTS = -smp $(QEMUSMP) -m 512 -serial mon:stdio -nographic \
 	-net user -net nic,model=e1000 \
-	-redir tcp:2323::23 -redir tcp:8080::80
+	-redir tcp:2323::23 -redir tcp:8080::80 \
+	$(if $(RUN),-append "\$$ $(RUN)",)

 qemu: $(KERN)
 	$(QEMU) $(QEMUOPTS) -kernel $(KERN)

--- a/bin/init.cc
+++ b/bin/init.cc
@@ -43,6 +43,30 @@ startone(const char **argv)
  return pid;
 }

+static void
+runcmdline(void)
+{
+  const char* argv[3] = { "sh", 0, 0 };
+  char buf[256];
+  char* b;
+  long r;
+  int fd;
+
+  fd = open("/dev/cmdline", O_RDONLY);
+  if (fd < 0)
+    return;
+
+  r = read(fd, buf, sizeof(buf)-1);
+  if (r < 0)
+    return;
+  buf[r] = 0;
+  
+  if ((b = strchr(buf, '$'))) {
+    argv[1] = b+1;
+    startone(argv);
+  }
+}
+
 int
 main(void)
 {
@@ -63,6 +87,8 @@ main(void)
  for (u32 i = 0; i < NELEM(app_argv); i++)
    startone(app_argv[i]);

+  runcmdline();
+
  for(;;){
    pid = startone(sh_argv);
    while((wpid=wait()) >= 0 && wpid != pid)

--- a/bin/sh.cc
+++ b/bin/sh.cc
@@ -142,7 +142,7 @@ getcmd(char *buf, int nbuf)
 }

 int
-main(void)
+main(int ac, char** av)
 {
  static char buf[100];
  int fd;
@@ -154,7 +154,30 @@ main(void)
      break;
    }
  }
-  
+
+  // If args, concatenate them parse as a command.
+  if (ac > 1) {
+    char* b = buf;
+    char* e = b+sizeof(buf);
+    for (int i = 1; i < ac; i++) {
+      int n;
+      n = strlen(av[i]);
+      if (b+n+1 > e)
+        die("sh: too long");
+      strcpy(b, av[i]);
+      b += n;
+      if (b+1+1 > e)
+        die("sh: too long");
+      strcpy(b, " ");
+      b++;
+    }
+
+    if(fork1() == 0)
+      runcmd(parsecmd(buf));
+    wait();
+    exit();
+  }
+
  // Read and run input commands.
  while(getcmd(buf, sizeof(buf)) >= 0){
    if(buf[0] == 'c' && buf[1] == 'd' && buf[2] == ' '){