add function to print information about available compressions tools

doc/src/Developer_platform.rst

@@ -42,6 +42,9 @@ Platform information functions
 .. doxygenfunction:: mpi_info
    :project: progguide
 
+.. doxygenfunction:: compress_info
+   :project: progguide
+
 
 File and path functions and global constants
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

src/info.cpp

@@ -309,6 +309,7 @@ void Info::command(int narg, char **arg)
 #else // defined(LAMMPS_SMALLSMALL)
     fputs("-DLAMMPS_SMALLSMALL\n",out);
 #endif
+    if (has_gzip_support()) fmt::print(out,"\n{}\n",platform::compress_info());
 
     int ncword, ncline = 0;
     fputs("\nInstalled packages:\n\n",out);

src/lammps.cpp

@@ -1379,6 +1379,8 @@ void LAMMPS::print_config(FILE *fp)
              sizeof(smallint)*8, sizeof(imageint)*8,
              sizeof(tagint)*8, sizeof(bigint)*8);
 
+  if (Info::has_gzip_support()) fmt::print(fp,"\n{}\n",platform::compress_info());
+
   fputs("\nInstalled packages:\n\n",fp);
   for (int i = 0; nullptr != (pkg = installed_packages[i]); ++i) {
     ncword = strlen(pkg);

src/platform.cpp

@@ -418,6 +418,24 @@ std::string platform::mpi_info(int &major, int &minor)
   return {version};
 }
 
+/* ----------------------------------------------------------------------
+   collect available compression tool info
+------------------------------------------------------------------------- */
+
+std::string platform::compress_info()
+{
+  std::string buf = "Available compression formats:\n\n";
+  bool none_found = true;
+  for (const auto &cmpi : compress_styles) {
+     if (cmpi.style == ::compress_info::NONE) continue;
+     if (find_exe_path(cmpi.command).size()) {
+       none_found = false;
+       buf += fmt::format("Extension: .{:6} Command: {}\n", cmpi.extension, cmpi.command);
+     }
+  }
+  if (none_found) buf += "None\n";
+  return buf;
+}
 /* ----------------------------------------------------------------------
    set environment variable
 ------------------------------------------------------------------------- */
@@ -930,7 +948,7 @@ bool platform::file_is_readable(const std::string &path)
 
 bool platform::has_compress_extension(const std::string &file)
 {
-  return find_compress_type(file).style != compress_info::NONE;
+  return find_compress_type(file).style != ::compress_info::NONE;
 }
 
 /* ----------------------------------------------------------------------
@@ -943,7 +961,7 @@ FILE *platform::compressed_read(const std::string &file)
 
 #if defined(LAMMPS_GZIP)
   auto compress = find_compress_type(file);
-  if (compress.style == compress_info::NONE) return nullptr;
+  if (compress.style == ::compress_info::NONE) return nullptr;
 
   if (find_exe_path(compress.command).size())
     // put quotes around file name so that they may contain blanks
@@ -962,7 +980,7 @@ FILE *platform::compressed_write(const std::string &file)
 
 #if defined(LAMMPS_GZIP)
   auto compress = find_compress_type(file);
-  if (compress.style == compress_info::NONE) return nullptr;
+  if (compress.style == ::compress_info::NONE) return nullptr;
 
   if (find_exe_path(compress.command).size())
     // put quotes around file name so that they may contain blanks

src/platform.h

@@ -109,6 +109,15 @@ namespace platform {
 
   std::string mpi_info(int &major, int &minor);
 
+  /*! Return string with list of available compression types and executables
+   *
+   * This function tests which of the supported compression executables
+   * are available for reading or writing compressed files where supported.
+   *
+   *  \return  string with list of available compression tools */
+
+  std::string compress_info();
+
   /*! Add variable to the environment
    *
    * \param  vardef  variable name or variable definition (NAME=value)