add possibility to append to output file instead of truncating

- add option file_append
- add default argument for file_append to various API functions
- closes #720

ChangeLog.md

@@ -15,6 +15,10 @@ More detailed information about incremental changes can be found in the
   Christoph Hansknecht].
 - Print additional messages when reallocation of MA27 working space failed
   [#671, by Daniel Oliveira].
+- Added option `file_append` to specify whether to append to `output_file` instead of
+  truncating it. Added default argument `file_append` to `Journalist::AddFileJournal()`,
+  added default argument `fappend` to `FileJournal::Open()`, and added default argument
+  `file_append` to `IpoptApplication::OpenOutputFile()`. [#720]
 
 ### 3.14.12 (2023-04-05)
 

src/Common/IpJournalist.cpp

@@ -264,14 +264,15 @@ bool Journalist::AddJournal(
 SmartPtr<Journal> Journalist::AddFileJournal(
    const std::string& journal_name,
    const std::string& fname,
-   EJournalLevel      default_level
+   EJournalLevel      default_level,
+   bool               file_append
 )
 {
    SmartPtr<FileJournal> temp = new FileJournal(journal_name, default_level);
 
    // Open the file (Note:, a fname of "stdout" is handled by the
    // Journal class to mean stdout, etc.
-   if( temp->Open(fname.c_str()) && AddJournal(GetRawPtr(temp)) )
+   if( temp->Open(fname.c_str(), file_append) && AddJournal(GetRawPtr(temp)) )
    {
       return GetRawPtr(temp);
    }
@@ -392,7 +393,10 @@ FileJournal::~FileJournal()
    file_ = NULL;
 }
 
-bool FileJournal::Open(const char* fname)
+bool FileJournal::Open(
+   const char* fname,
+   bool        fappend
+)
 {
    if( file_ && file_ != stdout && file_ != stderr )
    {
@@ -414,7 +418,7 @@ bool FileJournal::Open(const char* fname)
    else
    {
       // open the file on disk
-      file_ = fopen(fname, "w+");
+      file_ = fopen(fname, fappend ? "a+" : "w+");
       if( file_ )
       {
          return true;

src/Common/IpJournalist.hpp

@@ -231,7 +231,8 @@ class IPOPTLIB_EXPORT Journalist: public ReferencedObject
    virtual SmartPtr<Journal> AddFileJournal(
       const std::string& location_name,            /**< string identifier, which can be used to obtain the pointer to the new Journal at a later point using the GetJournal method */
       const std::string& fname,                    /**< name of the file to which this Journal corresponds; use "stdout" for stdout and use "stderr" for stderr */
-      EJournalLevel      default_level = J_WARNING /**< default journal level used to initialize the printing level for all categories */
+      EJournalLevel      default_level = J_WARNING,/**< default journal level used to initialize the printing level for all categories */
+      bool               file_append = false       /**< whether to append to file or truncate it (since 3.14.13) */
    );
 
    /** Get an existing journal.
@@ -432,7 +433,8 @@ class IPOPTLIB_EXPORT FileJournal: public Journal
     *  @return false only if the file with the given name could not be opened
     */
    virtual bool Open(
-      const char* fname
+      const char* fname,             /**< name of file to open */
+      bool        fappend = false    /**< whether to append or truncate file (since 3.14.13) */
    );
 
 protected:

src/Interfaces/IpIpoptApplication.cpp

@@ -227,7 +227,9 @@ ApplicationReturnStatus IpoptApplication::Initialize(
             {
                file_print_level = print_level;
             }
-            bool openend = OpenOutputFile(output_filename, file_print_level);
+            bool file_append;
+            options_->GetBoolValue("file_append", file_append, "");
+            bool openend = OpenOutputFile(output_filename, file_print_level, file_append);
             if( !openend )
             {
                jnlst_->Printf(J_ERROR, J_INITIALIZATION, "Error opening output file \"%s\"\n", output_filename.c_str());
@@ -386,6 +388,11 @@ void IpoptApplication::RegisterOptions(
       "NOTE: This option only works when read from the ipopt.opt options file! "
       "Determines the verbosity level for the file specified by \"output_file\". "
       "By default it is the same as \"print_level\".");
+   roptions->AddBoolOption(
+      "file_append",
+      "Whether to append to output file, if set, instead of truncating.",
+      false,
+      "NOTE: This option only works when read from the ipopt.opt options file!");
    roptions->AddBoolOption(
       "print_user_options",
       "Print all options set by the user.",
@@ -943,14 +950,15 @@ ApplicationReturnStatus IpoptApplication::call_optimize()
 
 bool IpoptApplication::OpenOutputFile(
    std::string   file_name,
-   EJournalLevel print_level
+   EJournalLevel print_level,
+   bool          file_append
 )
 {
    SmartPtr<Journal> file_jrnl = jnlst_->GetJournal("OutputFile:" + file_name);
 
    if( IsNull(file_jrnl) )
    {
-      file_jrnl = jnlst_->AddFileJournal("OutputFile:" + file_name, file_name.c_str(), print_level);
+      file_jrnl = jnlst_->AddFileJournal("OutputFile:" + file_name, file_name.c_str(), print_level, file_append);
    }
 
    // Check, if the output file could be created properly

src/Interfaces/IpIpoptApplication.hpp

@@ -180,8 +180,9 @@ class IPOPTLIB_EXPORT IpoptApplication: public ReferencedObject
     *  @return false if there was a problem
     */
    virtual bool OpenOutputFile(
-      std::string  file_name,
-      EJournalLevel print_level
+      std::string   file_name,             /**< name of file to open */
+      EJournalLevel print_level,           /**< print level to be used */
+      bool          file_append = false    /**< whether to append to file or truncate (since 3.14.13) */
    );
 
    /**@name Accessor methods */