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--- concatenate_strings_in_input_file [2011/06/16 16:51] – johnsoevans
+++ concatenate_strings_in_input_file [2025/09/19 15:18] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
+====== Joining strings in an input file ======
+You can concatanate strings in a text file to build up complex filenames etc using the following:
+<code topas>macro data_directory {c:\data\storage_directory\}
+macro file_stem {dataname_}
+macro run_number {0000}
+macro suffix {.xy}
+macro file_dets(data_directory, file_stem, run_number, suffix)
+{
+               data_directory##file_stem##run_number##suffix
+}
+macro file
+{
+               file_dets(data_directory, file_stem, run_number, suffix)
+}
+file</code>
+which will expand to:
+<code topas>c:\data\storage_directory\dataname_0000.xy
+</code>
+The ## concatenation sequence is a c pre-processor construct and only concatenates macro arguments hence the double step.
+Similarly you can e.g. change the name of an output .xy file with macros like:
+<code topas>macro lor { 1000 }
+macro File_Out_(n)
+{
+	voigt##n##.xy
+}
+Out_X_Ycalc(File_Out_(lor))</code>