c - 删除 .txt 文件中每行末尾的 ^M。

Question

我有以下内容

^XA^M
^SZ2^JMA^M
^MCY^PMN^M
^PW822~JSN^M
^JZY^M
^LH0,0^LRN^M
^XZ^M
^XA^M
^FO350,95^M
^BY4^BCB,220,N,N,N,A^FD12345^FS
^FT605,700^M
^A0B,40,40^M
^FB600,1,0,R,0^M
^FD12345^FS
^FT282,1160^M
^A0B,28,39^FDBilka Tilst afdelingen^FS
^FT320,1160^M
^A0B,28,39^FDAgerøvej 7^FS
^FT358,1160^M
^A0B,28,39^FDPort 39^FS
^FT396,1160^M
^A0B,28,39^FDTilst^FS
^FT434,1160^M
^A0B,28,39^FDFLD_COUNTY_FLD^FS^M
^FT472,1160^M
^A0B,28,39^FD8381^FS
^FT510,1160^M
^A0B,28,39^FDFLD_COUNTRY_FLD^FS^M
^FT548,1160^M
^A0B,28,39^FDFLD_ORDERTEL_FLD^FS^M
^FO660,100^M
^GB0,720,2^FS^M
^FO750,100^M
^GB0,720,2^FS^M
^FO660,820^M
^GB92,0,2^FS^M
^FO660,100^M
^GB92,0,2^FS^M
^FT680,810^M
^A0B,18,23^FDDELIVERY INSTRUCTIONS:^FS^M
^FT700,810^M
^A0B,18,25^FDFLD_SPECIALINST1_FLD^FS^M
^FT720,810^M
^A0B,18,25^FDFLD_SPECIALINST2_FLD^FS^M
^FT200,1160^M
^A0B,80,90^FB1160,2,0,L,0^FDFLD_SERVICETEXT_FLD^FS^M
^FT780,1160^M
^A0B,18,20^FDSender's address: ^FS^M

我试图删除每行末尾的 ^M，并在 C 中包含以下内容

GLOBAL BOOLEAN CARRIER_CONSIGNOR_SIM_ReplaceZPL(CARRIER_CONSIGNOR_SIM_ORDER_TYPE* Header)
{
  #define MAX_FILE_LEN 30

  char filename[MAX_FILE_LEN];
  snprintf(filename, MAX_FILE_LEN, "%s.zpl", Header->OrderNumber);

  FILE *file;
  FILE *write;
  char line  [256];
  char linec [256];

  file = fopen( filename, "r");
  write = fopen( filename, "r+");

  if( file != NULL )
  {
    while ( fgets ( line, sizeof line, file ) != NULL ) /* read a line */
    {
      strcpy(linec, line);
      fprintf (write , linec);
    }
    /* Close both files */
    fclose (write);
    fclose (file);
    printf("REPLACED LABEL in %s\n", filename);
    return ( TRUE );
  }

 return ( FALSE );
}/*CARRIER_CONSIGNOR_SIM_ReplaceZPL*/

我已尝试对“rb+”、“r+b 和 rb 执行以下操作以写入 = fopen，但这都不会删除 ^M。解决此问题的最佳方法是什么。

Answer 1

您可以通过删除末尾的 \r 或 \n 字符来缩短字符串，例如改变:

  ...
  strcpy(linec, line);
  ...

到:

  int len;
  ...
  strcpy(linec, line);
  len = strlen(linec);                   // get length of string
  while (len > 0)                        // while string not empty
  {                                      // if last char is \r or \n
      if (linec[len - 1] == '\r' || linec[len - 1] == '\n')
      {
          linec[len - 1] = '\0';         // delete it
          len--;
      }
      else                               // otherwise we found the last "real" character
          break;
  }
  ...

请注意，当您打印字符串时，您需要添加一个换行符，例如使用

fprintf(write, "%s\n", linec);