removeLineEndSpace

 /******************************************************************************
  *                          removeLineEndSpace
  *  声明：
  *      该程序是之前alignBySpace的逆向补充程序，去掉行尾的空格。
  *
  *                                   2015-8-11 阵雨 深圳 南山平山村 曾剑锋
  *****************************************************************************/
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>

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

     int    ret                      = ;
     char  *tempFile                 = "generateFile.txt";
     char  *readBuffer               = NULL;
     size_t bufferSize               = ;
     int    readBufferIndex          = ;

     if (  argc !=   ) {
         printf ( "USAGE:\n" );
         printf ( "   removeLineEndSpace <file>.\n" );
         return -;
     }

     FILE *readfile  = fopen ( argv[], "r" );                         // only read
     FILE *writefile = fopen ( tempFile, "w" );                        // only write

     /**
      * man datasheet:
      *    If *lineptr is NULL, then getline() will allocate a buffer for storing the line,
      *    which should be freed by the user program. (In this case, the value in *n is ignored.)
      */
     while ( ( ret = getline( &readBuffer, &bufferSize, readfile ) ) != - ) {

         readBufferIndex  = ret - ; // index for real position

         while ( ( readBuffer [ readBufferIndex ] == ' ' ) ||          // del ' ', '\t', '\n' character
                 ( readBuffer [ readBufferIndex ] == '\n' ) || ( readBuffer [ readBufferIndex ] == '\t' ) )
             readBuffer [ readBufferIndex-- ] = '\0';

         readBuffer [ readBufferIndex +  ] = '\n';

         fputs ( readBuffer, writefile );                              // write to file 

         bzero ( readBuffer,  ret );                                   // clean buffer
     }

     free ( readBuffer );                                              // referrence getline()

     fclose ( readfile );
     fclose ( writefile );

     remove ( argv[] );                                               // delete source file
     rename ( tempFile, argv[] );                                     // tempfile rename to source file
 }