[PATCH 2/2] getloadavg: don’t depend on fopen-gnu

[Paul Eggert]

This is for Emacs, which does not need fopen-gnu for anything else,
and which would need it only on a NetBSD platform where getloadavg
does not work (does that even happen?).
* lib/getloadavg.c (getloadavg) [__NetBSD__]: Use open, not fopen.
* modules/getloadavg (Depends-on): Remove fopen-gnu.
---
 ChangeLog          |  7 +++++++
 lib/getloadavg.c   | 21 ++++++++++++++-------
 modules/getloadavg |  1 -
 3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index cd194e0c4..19e609e31 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2020-06-27  Paul Eggert  <eggert@cs.ucla.edu>
 
+       getloadavg: don’t depend on fopen-gnu
+       This is for Emacs, which does not need fopen-gnu for anything else,
+       and which would need it only on a NetBSD platform where getloadavg
+       does not work (does that even happen?).
+       * lib/getloadavg.c (getloadavg) [__NetBSD__]: Use open, not fopen.
+       * modules/getloadavg (Depends-on): Remove fopen-gnu.
+
        * tests/test-getloadavg.c (main): Fix typo.
 
 2020-06-27  Bruno Haible  <bruno@clisp.org>
diff --git a/lib/getloadavg.c b/lib/getloadavg.c
index aeb7070cc..468e25067 100644
--- a/lib/getloadavg.c
+++ b/lib/getloadavg.c
@@ -567,15 +567,22 @@ getloadavg (double loadavg[], int nelem)
 
   unsigned long int load_ave[3], scale;
   int count;
-  FILE *fp;
-
-  fp = fopen (NETBSD_LDAV_FILE, "re");
-  if (fp == NULL)
-    return -1;
-  count = fscanf (fp, "%lu %lu %lu %lu\n",
+  char readbuf[4 * INT_BUFSIZE_BOUND (unsigned long int) + 1];
+  int fd = open (NETBSD_LDAV_FILE, O_RDONLY | O_CLOEXEC);
+  if (fd < 0)
+    return fd;
+  int nread = read (fd, readbuf, sizeof readbuf - 1);
+  int err = errno;
+  close (fd);
+  if (nread < 0)
+    {
+      errno = err;
+      return -1;
+    }
+  readbuf[nread] = '\0';
+  count = sscanf (readbuf, "%lu %lu %lu %lu\n",
                   &load_ave[0], &load_ave[1], &load_ave[2],
                   &scale);
-  (void) fclose (fp);
   if (count != 4)
     {
       errno = ENOTSUP;
diff --git a/modules/getloadavg b/modules/getloadavg
index a5a3c4e03..8adb9a784 100644
--- a/modules/getloadavg
+++ b/modules/getloadavg
@@ -7,7 +7,6 @@ m4/getloadavg.m4
 
 Depends-on:
 extensions
-fopen-gnu
 intprops
 open
 stdbool
-- 
2.17.1