37: expand

Implement the first command line tool, expand.

View Source file expand.cpp Only

// https://www.gnu.org/software/coreutils/manual/html_node/expand-invocation.html
#include <fmt/core.h>
#include <fstream>

void convert_file(std::istream& in, int tab_stop) {
  std::string in_line;

  while(in) {
    std::string out_line;
    getline(in, in_line);

    for(size_t i = 0; i < in_line.size(); i++) {
      char ch = in_line[i];

      if(ch == '\t') {
        out_line.append(tab_stop, ' ');
      } else {
        out_line += ch;
      }
    }

    fmt::println("{}", out_line);
  }
}

int main(int argc, char* argv[]) {
  for(int i = 1; i < argc; i++) {
    std::ifstream in_file{argv[i]};
    convert_file(in_file, 2);
  }
}