FENIX_coreutils/basename.c

#define _POSIX_C_SOURCE 200809L

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(int argc, char ** argv) {
  int suffix_present = 0, i, j;
  char *basename; char c;
  int basename_length = 0, last_slash = 0;
  int suffix_length = 0;

  if(argc > 2) {
    suffix_present = 1;
  }
  else if(argc == 1) {
    printf("\n");
    return 0;
  }

  if(strcmp(argv[1], "//") == 0) {
    printf("\n");
    return 0;
  }

  i = 0;
  
  for(c = argv[1][i]; c != '\0'; c = argv[1][i]) {
    i++;
  }

  if(argv[1][i-1] == '/') {
    argv[1][i-1] = '\0';
  }

  i = 0;
  
  for(c = argv[1][i]; c != '\0'; c = argv[1][i]) {
    if(c == '/') {
      last_slash = i;
    }
    i++;
  }

  i = last_slash + 1;

  for(c = argv[1][i]; c != '\0'; c = argv[1][i]) {
    basename_length++; i++;
  }

  basename = calloc(basename_length + 1, sizeof(*basename));
  if(basename == NULL) {
    fprintf(stderr, "%s: Could not allocate sufficient memory\n", argv[0]);
    return 1;
  }

  i = last_slash + 1;

  for(c = argv[1][i]; c != '\0'; c = argv[1][i]) {
    basename[i - (last_slash + 1)] = c;
    i++;
  }

  basename[basename_length] = '\0';

  if(suffix_present && strcmp(basename, argv[2]) != 0) {
    i = 0;
    for(c = argv[2][i]; c != '\0'; c = argv[2][i]) {
      suffix_length++;
      i++;
    }
    
    j = suffix_length - 1;

    for(i = basename_length - 1; i > 0; i--) {
      if(basename[i] != argv[2][j]) {
	break;
      }
      else if(j == 0) {
        basename[i] = '\0';
	i = 0;
      }
      j--;
    }
  }

  printf("%s\n", basename);

  free(basename);

  return 0;
}