代码集转换过滤器示例

本节将涵盖接受 ToCode 和 FromCode 参数的代码集转换过滤器。

下面的示例演示了如何使用这些子例程来创建一个代码集转换过滤器，并且该过滤器接收 ToCode 和 FromCode 参数作为输入自变量：

#include <stdio.h>
#include <nl_types.h>
#include <iconv.h>
#include <string.h>
#include <errno.h>
#include <locale.h>

#define ICONV_DONE() (r>=0)
#define ICONV_INVAL() (r<0) && (errno==EILSEQ))
#define ICONV_OVER() (r<0) && (errno==E2BIG))
#define ICONV_TRUNC() (r<0) && (errno==EINVAL))

#define USAGE 1
#define ERROR 2
#define INCOMP 3

char ibuf[BUFSIZ], obuf[BUFSIZ];

extern int errno;

main (argc,argv)
int argc;
char **argv;
{

 size_t  ileft,oleft;
 nl_catd catd;
 iconv_t cd;
 int r;
 char *ip,*op;

 setlocale(LC_ALL,"");
 catd = catopen (argv[0],0);

 if(argc!=3){
  fprintf(stderr,
   catgets (catd,NL_SETD,USAGE,"usage;conv fromcode tocode\n"));
  exit(1);
 }

 cd=iconv_open(argv[2],argv[1]);

ileft=0;

while(!feof(stdin)) {

 /*
 * After the next operation,ibuf will
 * contain new data plus any truncated
 * data left from the previous read.
 */
 ileft+=fread(ibuf+ileft,1,BUFSIZ-ileft,stdin);
 do {
  ip=ibuf;
  op=obuf;
  oleft=BUFSIZ;

  r=iconv(cd,&ip,&ileft,&op,&oleft);

  if(ICONV_INVAL()){
   fprintf(stderr,
      catgets(catd,NL_SETD,ERROR,"invalid input\n"));
   exit(2);
 }

 fwrite(obuf,1,BUFSIZ-oleft,stdout);

 if(ICONV_TRUNC() || ICONV_OVER())
  /*
  *Data remaining in buffer-copy
  *it to the beginning
  */

  memcpy(ibuf,ip,ileft);

  /*
  *loop until all characters in the input
  *buffer have been converted.
  */
 } while(ICONV_OVER());
}

 if(ileft!=0){
  /*
  *This can only happen if the last call
  *to iconv() returned ICONV_TRUNC, meaning
  *the last data in the input stream was
  *incomplete.
  */
 fprintf(stderr,catgets(catd,NL_SETD,INCOMP,"input incomplete\n"));
 exit(3);
 }

 iconv_close(cd);
 exit(0);
}