progs/cc-progress.c: Use `fstat' to discover the file size.

And `lseek' to discover the current offset.  Annoyingly, Android only
developed `ftello64' and `fseeko64' in API24, so we can't use these (and
it was a pretty grim circumlocution anyway).  On the other hand, Android
has had `lseek64' forever, and its `fstat' is natively 64-bit; and
there's no portability benefit to using the other functions because
Windows doesn't have them anyway.  (Indeed, `lseek' and `stat' are
ancient Unix, so probably more portable.)

diff --git a/progs/cc-progress.c b/progs/cc-progress.c
index 918eb2c..055556c 100644 (file)
--- a/progs/cc-progress.c
+++ b/progs/cc-progress.c
@@ -31,6 +31,8 @@
 
 #include "config.h"
 
+#include <unistd.h>
+
 #include "cc.h"
 
 #ifndef PATHSEP
@@ -129,16 +131,15 @@ static void prhuman_data(FILE *fp, off_t n)
 int fprogress_init(fprogress *f, const char *name, FILE *fp)
 {
   const char *p;
+  struct stat st;
   off_t o, sz = -1;
   size_t n;
 
   /* --- Set up the offset --- */
 
-  if ((o = ftello(fp)) >= 0 &&
-      fseeko(fp, 0, SEEK_END) >= 0 &&
-      (sz = ftello(fp),
-       fseeko(fp, o, SEEK_SET) < 0))
-    return (-1);
+  o = lseek(fileno(fp), 0, SEEK_CUR);
+  if (fstat(fileno(fp), &st)) return (-1);
+  sz = (S_ISREG(st.st_mode)) ? st.st_size : -1;
   if (o != -1 && sz != -1) sz -= o;
   f->o = f->olast = 0; f->sz = sz;