Combine two strings without modifying them

Hey,
I've been trying to combine two strings into a third one without modifying the original two. Heres the code I've got, but it wont compile:

char rho_dir[50], vel_dir[50];
char outputpath[50] = "./path/to/directory/"

rho_dir = strcpy(rho_dir,strcat(strdup(outputpath),"fields_r ho"));
vel_dir = strcpy(vel_dir,strcat(strdup(outputpath),"fields_v el"));

I want to set the variables rho_dir = "./path/to/directory/fields_rho" and vel_dir = "./path/to/directory/fields_vel" without changing the string outputpath. Am I being insanely thick but I can't see an easy way to do it.

Thanks alot,
Kieran

1. use strcpy + strcat
2. use sprintf

Code:

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sprintf(rho_di,"%s%s", outputpath,"fields_rho");

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