Add version ID, in addtion to existing version string.

Closes #253

dev/release/release_check.sh

@@ -122,7 +122,8 @@ function check_versions {
     echo
     echo "Latest file versions: "
 
-    grep -He "[0-9]\.[0-9]\.[0-9]" include/xlsxwriter.h libxlsxwriter.podspec | sed 's/:/ : /g' | awk '{printf "    | %-24s %s\n", $1, $5}'
+    grep -He "[0-9]\.[0-9]\.[0-9]"       include/xlsxwriter.h libxlsxwriter.podspec | sed 's/:/ : /g' | awk '{printf "    | %-24s %s\n", $1, $5}'
+    grep -He "LXW_VERSION_ID [0-9][0-9]" include/xlsxwriter.h                       | sed 's/:/ : /g' | awk '{printf "    | %-24s %s\n", $1, $5}'
 
     echo
     echo -n     "Are the versions up to date?           [y/N]: "

dev/release/update_revison.pl

@@ -24,7 +24,15 @@ while (<>) {
         }
 
         my $new_version = $version->stringify();
-        s/(\d\.\d\.\d)/$new_version/;
+        s/\d\.\d\.\d/$new_version/;
+    }
+
+    # Increment the LXW_VERSION_ID number in xlsxwriter.h
+    if (m/LXW_VERSION_ID (\d+)/) {
+        my $version = $1;
+        my $new_version = $version + 1;
+
+        s/\d+/$new_version/;
     }
 
     print;

include/xlsxwriter.h

@@ -19,5 +19,6 @@
 #include "xlsxwriter/utility.h"
 
 #define LXW_VERSION "0.8.8"
+#define LXW_VERSION_ID 88
 
 #endif /* __LXW_XLSXWRITER_H__ */

include/xlsxwriter/utility.h

@@ -103,6 +103,20 @@ extern "C" {
  */
 const char *lxw_version(void);
 
+/**
+ * @brief Retrieve the library version ID.
+ *
+ * @return The version ID.
+ *
+ * Get the library version such as "X.Y.Z" as a XYZ integer.
+ *
+ *  @code
+ *      printf("Libxlsxwriter version id = %d\n", lxw_version_id());
+ *  @endcode
+ *
+ */
+uint16_t lxw_version_id(void);
+
 /**
  * @brief Converts a libxlsxwriter error number to a string.
  *

src/utility.c

@@ -562,7 +562,7 @@ lxw_sprintf_dbl(char *data, double number)
 #endif
 
 /*
- * Retrieve runtime library version
+ * Retrieve runtime library version.
  */
 const char *
 lxw_version(void)
@@ -570,6 +570,15 @@ lxw_version(void)
     return LXW_VERSION;
 }
 
+/*
+ * Retrieve runtime library version ID.
+ */
+uint16_t
+lxw_version_id(void)
+{
+    return LXW_VERSION_ID;
+}
+
 /*
  * Hash a worksheet password. Based on the algorithm provided by Daniel Rentz
  * of OpenOffice.