Add a fd_readable(int fd) helper function

Use it instead of direct calls to select scatered around the code
base.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/file.cc b/src/file.cc
index f8928243..1bd0406e 100644
--- a/src/file.cc
+++ b/src/file.cc
@@ -13,6 +13,7 @@
 #include <unistd.h>
 #include <dirent.h>
 #include <stdlib.h>
+#include <sys/select.h>
 
 #if defined(__FreeBSD__)
 #include <sys/sysctl.h>
@@ -123,6 +124,16 @@ String compact_path(StringView filename)
     return filename.str();
 }
 
+bool fd_readable(int fd)
+{
+    fd_set  rfds;
+    FD_ZERO(&rfds);
+    FD_SET(fd, &rfds);
+
+    timeval tv{0,0};
+    return select(fd+1, &rfds, nullptr, nullptr, &tv) == 1;
+}
+
 String read_fd(int fd, bool text)
 {
     String content;