making a WC utility on command line

i am new to C programming and I am making a utility called word-count or wc from scratch.

i am using a command line argument in bash terminal like this:
./wc_app -c -l -w -n ex/foo.txt ex/bar.txt

-c -> for character count
-l -> line count
-w -> word count
-n -> number count

i am reading two files(input- foo.txt and bar.txt) and writing to a output file. in this format:
ex/foo.txt: 125 12 29 13
ex/bar.txt: 125 12 29 13

FOO.txt:
qwe 12 rtyu 34 iop
asdf 5 ghjkl6
7 zxc 8vbnm
90

BAR.txt:
Iro ha nihoheto
Chirinuru wo
Wa ka yo tare so
Tsune naramu
Uwi no okuyama
Kefu koete
Asaki yume mishi
Wehi mo sesu

here is my pseudocode:

1. Process command line flags using getopt.
2. Loop over the filename arguments
   
   1. Open the indicated file (with any error handling)
   2. Loop over the lines of the file
      
      1. Adjust your count of lines and characters.
      2. Count words
      3. Count numbers
      
      
   3. Print the file’s results (properly formatted)
   4. Close the input file
   
   
3. Print totals
4. Close the output file

WC_APP:

Code:

---

#include"main.h"
#include<stdlib.h>
// this is a sort of "from-scratch challenge"
// instructions on what the program should do are on the site
// (specifics are a way too involved for a pre-function comment, sorry. -蛇)
int main(int argc, char **argv)
{
  int opt;

  char *line_buf = NULL;
  size_t line_buf_size = 0;
  ssize_t line_size_fp;
  int line_count = 0;

  int chars_total = 0;
  int word_count = 0;
  int integer_count = 0;

  while ((opt = getopt(argc, argv, "cwnlo:f:")) != -1)  //proccess comand line flags
  {
    for (int i = 5; i < argc; i++)  //Loop over the filename arguments ./wc_lite_app -c -l -w -n ex/foo.txt ex/bar.txt
    {
      FILE *file_fp = fopen(argv, "r");
      if ((file_fp == NULL)) {
        fprintf(stderr, "%s: No such file or directory\n", argv);
        return 0;
      } else {
        line_size_fp = getline(&line_buf, &line_buf_size, file_fp);
        char *token = strtok(line_buf, " ");
        while (line_size_fp >= 0) {
          switch (opt) {
          case 'c':
            // printf("%s\n", line_buf);
            if () {
              line_size_fp = getline(&line_buf, &line_buf_size, file_fp);
              chars_total += line_size_fp;
            } else if (argv == 6) {
              line_size_fp = getline(&line_buf, &line_buf_size, file_fp);
              chars_total += line_size_fp;
            }

            break;
          case 'w':
            line_size_fp = getline(&line_buf, &line_buf_size, file_fp);

            token = strtok(line_buf, " ");
            while (token != NULL) {
              // printf("%s\n", token);
              token = strtok(NULL, " \n");
              word_count++;
            }
            break;
          case 'n':
            line_size_fp = getline(&line_buf, &line_buf_size, file_fp);
            token = strtok(line_buf, "1234567890");
            while (token != NULL) {
              // printf("%s\n", token);
              token = strtok(NULL, "1234567890");
              integer_count++;
            }
            break;
          case 'l':
            line_count++;
            line_size_fp = getline(&line_buf, &line_buf_size, file_fp);
            break;
          default:
            break;
          }

        }
      }
    }

  }
  printf("%s: %5d %5d %5d %5d\n", argv[5], chars_total, line_count, word_count,
        integer_count);
  printf("%s: %5d %5d %5d %5d\n", argv[6], chars_total, line_count, word_count,
        integer_count);

}

---

Your pseudo code looks fairly reasonable, but your actual code bears almost no resemblance to it (and is just plain wrong in many places).

Start by pasting the pseudo-code into code.

Code:

---

int main ( ) {
    // Process command line flags using getopt.
    // Loop over the filename arguments
        // Open the indicated file (with any error handling)
        // Loop over the lines of the file
            //Adjust your count of lines and characters.
            //Count words
            //Count numbers

        // Print the file’s results (properly formatted)
        // Close the input file

    // Print totals
    // Close the output file
}

---

Then fill in one step at a time

Code:

---

int main ( int argc, char *argv ) {
    // Process command line flags using getopt.
    while ((opt = getopt(argc, argv, "cwnlo:f:")) != -1) {
    }
    // Loop over the filename arguments
        // Open the indicated file (with any error handling)
        // Loop over the lines of the file
            //Adjust your count of lines and characters.
            //Count words
            //Count numbers

        // Print the file’s results (properly formatted)
        // Close the input file

    // Print totals
    // Close the output file
}

---

For each cwnl option, you want a boolean flag variable.
These four flag variables you test in your "Loop over the lines of the file".

Next, you implement ONE of the flags (counting lines is easy, so do that).
Make sure it works before adding more and more code.