provide POSIX_FADV_SEQUENTIAL hint to appropriate utils

Following on from commit dae35bac, 01-03-2010,
"sort: inform the system about our input access pattern"
apply the same hint to all appropriate utils.
This currently gives around a 5% speedup for reading
large files from fast flash devices on GNU/Linux.

* src/base64.c: Call fadvise (..., FADVISE_SEQUENTIAL);
* src/cat.c: Likewise.
* src/cksum.c: Likewise.
* src/comm.c: Likewise.
* src/cut.c: Likewise.
* src/expand.c: Likewise.
* src/fmt.c: Likewise.
* src/fold.c: Likewise.
* src/join.c: Likewise.
* src/md5sum.c: Likewise.
* src/nl.c: Likewise.
* src/paste.c: Likewise.
* src/pr.c: Likewise.
* src/ptx.c: Likewise.
* src/shuf.c: Likewise.
* src/sum.c: Likewise.
* src/tee.c: Likewise.
* src/tr.c: Likewise.
* src/tsort.c: Likewise.
* src/unexpand.c: Likewise.
* src/uniq.c: Likewise.
* src/wc.c: Likewise, unless we don't actually read().

1 files changed, 3 insertions, 0 deletions

diff --git a/src/tee.c b/src/tee.c
index 39d989274..a5b0369fd 100644
--- a/src/tee.c
+++ b/src/tee.c
@@ -23,6 +23,7 @@
 
 #include "system.h"
 #include "error.h"
+#include "fadvise.h"
 #include "stdio--.h"
 #include "xfreopen.h"
 
@@ -157,6 +158,8 @@ tee_files (int nfiles, const char **files)
   if (O_BINARY && ! isatty (STDOUT_FILENO))
     xfreopen (NULL, "wb", stdout);
 
+  fadvise (stdin, FADVISE_SEQUENTIAL);
+
   /* In the array of NFILES + 1 descriptors, make
      the first one correspond to standard output.   */
   descriptors[0] = stdout;