Strictly speaking, they are available in POSIX.1-2008 [1][2], so they
could be used on more platforms/OSes. To be cautious, enable them when
using GNU libc, since they have been available with that libc for a
very long time.
[1] https://pubs.opengroup.org/onlinepubs/
9699919799/functions/ftell.html
[2] https://pubs.opengroup.org/onlinepubs/
9699919799/functions/fseek.html
int64_t pos;
if (!f)
return JS_EXCEPTION;
-#if defined(__linux__)
+#if defined(__linux__) || defined(__GLIBC__)
pos = ftello(f);
#else
pos = ftell(f);
return JS_EXCEPTION;
if (JS_ToInt32(ctx, &whence, argv[1]))
return JS_EXCEPTION;
-#if defined(__linux__)
+#if defined(__linux__) || defined(__GLIBC__)
ret = fseeko(f, pos, whence);
#else
ret = fseek(f, pos, whence);