Getting absolute path of a file

Question

How can I convert a relative path to an absolute path in C on Unix? Is there a convenient system function for this?

On Windows there is a GetFullPathName

Answer 1

Try realpath() in stdlib.h

char filename[] = "../../../../data/000000.jpg";
char* path = realpath(filename, NULL);
if(path == NULL){
    printf("cannot find file with name[%s]\n", filename);
} else{
    printf("path[%s]\n", path);
    free(path);
}