Don't use readlinkat if it does not exist

This fixes bug #377.

diff --git a/configure.ac b/configure.ac
index 857e4ba84973a08674ceb7efd29da10ef765a6f2..22c47ce4ebfe2d41f1109562f72ef4f331dd2391 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -119,6 +119,9 @@ AC_CHECK_MEMBERS([struct termios.c_ispeed, struct termios.c_ospeed],
 AC_CHECK_MEMBERS([struct termios2.c_ispeed, struct termios2.c_ospeed],
        [AC_DEFINE(HAVE_TERMIOS2_SPEED, 1)], [], [[#include <linux/termios.h>]])
 
+# Check for readlinkat.
+AC_CHECK_FUNC([readlinkat], [AC_DEFINE(HAVE_READLINKAT, 1)], [])
+
 saved="$CFLAGS"; CFLAGS="$CFLAGS -Werror"
 AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
                __attribute__((visibility("hidden"))) void foo(void) { }

diff --git a/linux.c b/linux.c
index 9274e365040ad9f90ee7a6d09cdeaa372afe9571..d70a45f90a2260041c9d1722daa192bb69f55faa 100644 (file)
--- a/linux.c
+++ b/linux.c
@@ -161,6 +161,9 @@ SP_PRIV enum sp_return list_ports(struct sp_port ***list)
        char name[PATH_MAX], target[PATH_MAX];
        struct dirent entry, *result;
        struct serial_struct serial_info;
+#ifndef HAVE_READLINKAT
+       char buf[sizeof(entry.d_name) + 16];
+#endif
        int len, fd, ioctl_result;
        DIR *dir;
        int ret = SP_OK;
@@ -171,7 +174,12 @@ SP_PRIV enum sp_return list_ports(struct sp_port ***list)
 
        DEBUG("Iterating over results");
        while (!readdir_r(dir, &entry, &result) && result) {
+#ifdef HAVE_READLINKAT
                len = readlinkat(dirfd(dir), entry.d_name, target, sizeof(target));
+#else
+               snprintf(buf, sizeof(buf), "/sys/class/tty/%s", entry.d_name);
+               len = readlink(buf, target, sizeof(target));
+#endif
                if (len <= 0 || len >= (int) sizeof(target)-1)
                        continue;
                target[len] = 0;