ful2hlf.c

将文本中的全角转变为半角

/* convert full angle HZ to half angle HZ */

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

#define MAXLINE 65536 

int isBJ(unsigned char ch)   /* half angle ASCII character */
{
    return !(ch & 0x80);
}

int main(int argc, char *argv[])
{
  int i;
  unsigned char line[MAXLINE];
  int len;
  FILE *fp;
  unsigned char BFH[3] = "％";
  unsigned char DOT[3] = "．";

  if (argc != 2) {
    printf("Usage: %s all.txt\n", argv[0]);
    exit(-1);
  }

  fp = fopen(argv[1], "r");
  if (fp == NULL) {printf("Cannot open: %s\n", argv[1]); return -1;}

  while( fscanf(fp, "%s", line) != EOF )
  {
	  len = strlen(line);
	  for (i = 0; i < len; i++) {
		  if(!isBJ(line[i])) {
			  if (line[i] == 0xa3 && line[i+1] >= 0xb0 && line[i+1] <= 0xb9) /* digital 0-9 */
				  printf("%c", line[i+1] & 0x7f);
			  else if(line[i] == BFH[0] && line[i+1] == BFH[1]) /* % */
				  printf("%%");
			  else if(line[i] == DOT[0] && line[i+1] == DOT[1]) /* . */
				  printf(".");
			  else 
				  printf("%c%c", line[i], line[i+1]);
			  i++;
		  }
		  else
			  printf("%c", line[i]);
	  }
	  printf("\n");
  }
  return 0; 
}