1 files changed, 36 insertions, 0 deletions
diff --git a/src/common/lock.cpp b/src/common/lock.cpp
new file mode 100644
index 0000000..2ba9a0a
--- /dev/null
+++ b/src/common/lock.cpp
@@ -0,0 +1,36 @@
+#include <unistd.h>
+#include <stdio.h>
+#include "lock.hpp"
+#include "socket.hpp"
+
+/// Protected file writing
+/// (Until the file is closed, it keeps the old file)
+
+// Start writing a tmpfile
+FILE *lock_fopen (const char *filename, int *info)
+{
+    char newfile[512];
+    FILE *fp;
+    int  no = getpid ();
+
+    // Get a filename that doesn't already exist
+    do
+    {
+        sprintf (newfile, "%s_%d.tmp", filename, no++);
+    }
+    while ((fp = fopen_ (newfile, "r")) && (fclose_ (fp), 1));
+    *info = --no;
+    return fopen_ (newfile, "w");
+}
+
+// Delete the old file and rename the new file
+void lock_fclose (FILE * fp, const char *filename, int *info)
+{
+    char newfile[512];
+    if (fp)
+    {
+        fclose_ (fp);
+        sprintf (newfile, "%s_%d.tmp", filename, *info);
+        rename (newfile, filename);
+    }
+}