Question

I have an API function that takes constant char * as an input. I have to create a delimited text file which is the input of the function like:

193.875 0.0     0.0     2
193.876 0.0     0.0     2
193.877 0.0     0.0     2
193.878 0.0     0.0     2
193.879 0.0     0.0     2
193.880 0.0     0.0     2
193.881 0.0     0.0     2

the support guy of the software told me that I can create and save every line of this file by using sprintf() so I used it like:

sprintf(wsp,"%.3f\t0.0\t0.0\t%d\n", start_freq, z);

and after putting this line in loop I saved every created wsp in an array of string:

for (int j = 0; j < start; j++){

sprintf(wsp,"%.3f\t0.0\t0.0\t%d\n", start_freq, z);
start_freq = start_freq + 0.001;
wspfile[j] = wsp;

}

now I have a file with the required format but comes in array of string. My question is after creating the array how can I pass this array as a constant char * or how can I convert it to constant char *

Answer 1

You could make wspFile an std::string instead of an array. Then instead of

wspFile[j]=wsp;

you would have

wspFile+=wsp;

Then to get the const char* version you would call

wspFile.c_str();