setpgrp() when nosetsid contains "setpgrp" (asked by Buck Evans)

1 files changed, 11 insertions, 2 deletions

diff --git a/src/supervision/s6-supervise.c b/src/supervision/s6-supervise.c
index 80b7959..fa2cff9 100644
--- a/src/supervision/s6-supervise.c
+++ b/src/supervision/s6-supervise.c
@@ -6,6 +6,7 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
+#include <strings.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
@@ -188,18 +189,26 @@ static void killy (void)
 
 static void failcoe (int fd)
 {
-  register int e = errno ;
+  int e = errno ;
   fd_write(fd, "", 1) ;
   errno = e ;
 }
 
 static int maybesetsid (void)
 {
-  if (access("nosetsid", F_OK) < 0)
+  char buf[8] = "-------" ;
+  ssize_t r = openreadnclose("nosetsid", buf, 8) ;
+  if (r < 0)
   {
     if (errno != ENOENT) return 0 ;
     setsid() ;
   }
+  else
+  {
+    if (r == 8 && buf[7] == '\n') buf[--r] = 0 ;
+    if (r == 7 && !strncasecmp(buf, "setpgrp", 7))
+      setpgrp() ;
+  }
   return 1 ;
 }