Implement re-exec

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 38 insertions, 1 deletions

diff --git a/src/util.c b/src/util.c
index f73634a..5cbe44b 100644
--- a/src/util.c
+++ b/src/util.c
@@ -82,7 +82,11 @@ void* nread(int fd, size_t* n)
       
       got = read(fd, buf + *n, size - *n);
       if (got < 0)
-	goto fail;
+	{
+	  if (errno == EINTR)
+	    continue;
+	  goto fail;
+	}
       if (got == 0)
 	break;
       *n += (size_t)got;
@@ -99,6 +103,39 @@ void* nread(int fd, size_t* n)
 
 
 /**
+ * Write an entire buffer to a file
+ * 
+ * Not cancelled by `EINTR`
+ * 
+ * @param   fd   The file descriptor
+ * @param   buf  The buffer which shall be written to the fail
+ * @param   n    The size of the buffer
+ * @return       The number of written bytes, less than `n`
+ *               on error, cannot exceed `n`
+ */
+size_t nwrite(int fd, const void* buf, size_t n)
+{
+  const char* bs = buf;
+  ssize_t wrote;
+  size_t ptr = 0;
+  
+  while (ptr < n)
+    {
+      wrote = write(fd, bs + ptr, n - ptr);
+      if (wrote <= 0)
+	{
+	  if ((wrote < 0) && (errno == EINTR))
+	    continue;
+	  return ptr;
+	}
+      ptr += (size_t)wrote;
+    }
+  
+  return ptr;
+}
+
+
+/**
  * Duplicate a file descriptor an make sure
  * the new file descriptor's index as a
  * specified minimum value