C语言中使用lex统计文本文件字符数

我曾经在Linux上写的一个C程序，借助Lex做词法分析来同时统计N个文本文件的字符数，单词数和行数。让我觉得Lex确实挺有意思的。确实Lex的功能非常强大，用来做小巧的词法分析非常适合，也非常好用。这个程序参考了《Lex与Yacc》上的一个例子。

%{
unsigned int char_count = 0, word_count = 0, line_count = 0;
%}
%%
[^ /t/n]+ {word_count++; char_count+=yyleng;};
/n {char_count++; line_count++;};
. char_count++;
%%
char **file_list;
unsigned int current_file = 0;
unsigned int total_file = 0; 

unsigned int total_cc = 0;
unsigned int total_wc = 0;
unsigned int total_lc = 0; 

typedef struct file_info{
  unsigned int c;
  unsigned int w;
  unsigned int l;
  char *name;
}INFO; 

INFO **all; 

int create_info(int num)
{
  INFO *tmp;
  int i;
  if (num <= 0){
    return -1;
  }
  all = (INFO **)malloc(sizeof(int *)*num);
  for (i = 0; i < num; i++){
    tmp = (INFO *)malloc(sizeof(INFO));
    tmp->c = 0;
    tmp->w = 0;
    tmp->l = 0;
    tmp->name = NULL;
    all[i] = tmp;
  }
  return 1;
}   

int delete_info(int num)
{
  int i;
  if ((all == (INFO **)0) || num <= 0){
    return -1;
  }
  for (i = 0; i < num; i++){
    free(all[i]);
  }
  free(all);
  return 1;
} 

int set_info(int pos)
{
  int length = 0;
  if (pos < 0){
    return -1;
  }
  all[pos]->c = char_count;
  all[pos]->w = word_count;
  all[pos]->l = line_count;
  all[pos]->name = file_list[pos]; 

  return 1;
} 

int main(int argc, char** argv)
{
  FILE *file;
  int position = 0;
  int i; 

  file_list = argv + 1;
  total_file = argc - 1;
  current_file = 0; 

  printf("--------------------------------------------------------------/n",
 total_file);  

  if (argc > 1){
    if (create_info(total_file) == -1){
      fprintf(stderr, "%s/n", "Encounter a error when malloc memory."); 

      exit(1);
    }
  }
  if (argc == 2){        

    file=fopen(argv[1], "r");
    if (!file){
      fprintf(stderr, "Could not open %s./n", argv[1]);
      delete_info(total_file);
      exit(1);
    }
    yyin = file;
  } 

  yywrap();
  yylex(); 

  if (argc > 1){
    total_cc += char_count;
    total_wc += word_count;
    total_lc += line_count;     

    if (set_info(current_file-1) == -1){
      fprintf(stderr, "%s/n", "Encounter a error when set information to
 INFO.");
      delete_info(total_file);
      exit(1);
    }     

    for (i = 0; i < total_file; i++){
      printf("char:%-8lu word:%-8lu line:%-8lu file name:%s/n", all[i]->
c, all[i]->w, all[i]->l, file_list[i]);
    }
    printf("----------------------- total --------------------------------
/n");
    printf("chars:%-8lu words:%-8lu lines:%-8lu files:%d/n", total_cc, tot
al_wc, total_lc, total_file);
  }else{
    printf("char:%-8lu word:%-8lu line:%-8lu/n", char_count, word_count, l
ine_count);
  } 

  delete_info(total_file);
  return 0;
} 

yywrap()
{
  FILE *file = NULL; 

  if ((current_file > 0) && (current_file < total_file) && (total_file > 1))
{
    total_cc += char_count;
    total_wc += word_count;
    total_lc += line_count; 

    if (set_info(current_file-1) == -1){
      fprintf(stderr, "%s/n", "Encounter a error when set information to
 INFO.");
      delete_info(total_file);
      exit(1);
    }   

    char_count = word_count = line_count = 0;
    fclose(yyin);
  }
  while ((file_list[current_file] != (char *)0) && (current_file < total_fil
e)){ 

    file = fopen(file_list[current_file++], "r");
    if (!file){
      fprintf(stderr, "could not open %s .", file_list[current_file - 1]
);
    }else{
      yyin = file;
      break;
    }
  }
  return (file? 0 : 1);
}