Replace many calls to sprintf with QUtil::hex_encode

Add QUtil::hex_encode to encode binary data has a hexadecimal string,
and use it in place of sprintf where possible.

1 files changed, 6 insertions, 0 deletions

diff --git a/include/qpdf/QUtil.hh b/include/qpdf/QUtil.hh
index ddba97de..9639917d 100644
--- a/include/qpdf/QUtil.hh
+++ b/include/qpdf/QUtil.hh
@@ -56,6 +56,12 @@ namespace QUtil
     QPDF_DLL
     char* copy_string(std::string const&);
 
+    // Returns lower-case hex-encoded version of the string, treating
+    // each character in the input string as unsigned.  The output
+    // string will be twice as long as the input string.
+    QPDF_DLL
+    std::string hex_encode(std::string const&);
+
     // Set stdin, stdout to binary mode
     QPDF_DLL
     void binary_stdout();