空格填充器(alignBySpace)

 /*******************************************************************
  *                     空格填充器(alignBySpace)
  * 声明：
  *  1. 软件主要是在不改变文本文件内容情况下，自动填充空格一定数量的
  *      空格，达到空格右对齐的功能；
  *  2. 本软件主要是节省个人的代码跟踪文档打空格的时间；
  *
  *                             2015-8-3 晴 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                      = ;
     int    column                   = ;
     char  *tempFile                 = "generateFile.txt";
     char  *readBuffer               = NULL;
     size_t bufferSize               = ;
     int    readBufferIndex          = ;
     int    writeBufferIndex         = ;
     char   writeBuffer[bufferSize];

     if ( ( argc <  ) || ( argc >  ) ) {
         printf ( "USAGE:\n" );
         printf ( "    alignBySpace <file> [column].\n" );
         return -;
     }

     if ( argc ==  ) {
         printf ( "\nUse default columns: 80. \n\n" );
         column = ;
     } else
         column = atoi ( argv[] );

     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  = ;
         writeBufferIndex = ;

         while ( readBufferIndex < ret ) {
             if ( readBuffer [ readBufferIndex ] != '\t' )             // kick out '\t'
                 writeBuffer [ writeBufferIndex++ ] = readBuffer [ readBufferIndex++ ];
             else {
                 memset ( writeBuffer + writeBufferIndex, ' ',  );    // every tab key was 4 space
                 writeBufferIndex += ;
                 readBufferIndex++;
             }
         }

         writeBufferIndex--;                                           // back to real index

         if ( ( column - writeBufferIndex ) >  ) {                    // may be real column longer than we set
             // '\n' at end of a line, need to kick it out
             memset ( writeBuffer + writeBufferIndex, ' ', column - writeBufferIndex );
             writeBuffer [ column ] = '\n';                            // for end of a line
             writeBuffer [ column +  ] = '\0';                        // for end of a string
         } else
             writeBuffer [ writeBufferIndex +  ] = '\0';              // make sure end of a string

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

         bzero ( readBuffer,  bufferSize );                            // clean buffer
         bzero ( writeBuffer, bufferSize );

     }

     free ( readBuffer );                                              // referrence getline()

     fclose ( readfile );
     fclose ( writefile );

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