test4.c

#include <stdio.h>
#include <stdlib.h>
#include "array.h"

/* This program will fill an array of structures of size 100 with 
 * a bunch of names from the file "names.txt".
 * It will then write the name to the file "names2.txt", as lastname, 
 * firstname; then it will remove the last item using "contract",
 * and finally report the number of read, write, malloc and free 
 * calls.
 */

#define	CAPACITY	100	// total capacity of the array

struct Name
{
  char first[25];
  char last[25];
};

void readFile( struct Performance *performance, struct Array *array )
{
  FILE *fp;
  char buffer[81];
  struct Name name;
  int retval;

  fp = fopen( "names.txt", "r" );

  // skip the first line
  fgets( buffer, 80, fp );

  while (!feof(fp))
  {
    // this scanf call is unsafe if inputs are wider the first or last strings
    retval = fscanf( fp, "%s %s", name.first, name.last );

    if (retval==2)
    {
      writeItem( performance, array, array->nel, &name );
    }
  }

  fclose( fp );
}

int main( int argc, char **argv )
{
  struct Name name;
  struct Performance *perf;
  struct Array *array;
  int i;
  FILE *fp;

  perf = newPerformance();
  array = newArray( perf, sizeof( struct Name ), CAPACITY );

  readFile( perf, array );

  printf( "Read %d records\n", array->nel );

  fp = fopen( "names2.txt", "w" );
  for (i=0;i<array->nel;i++)
  {
    readItem( perf, array, i, &name );
    fprintf( fp, "%s, %s\n", name.last, name.first );
  }
  fclose( fp );

  contract( perf, array );
  printf( "After contraction:\n" );

  for (i=0;i<array->nel;i++)
  {
    readItem( perf, array, i, &name );
    printf( "%2d:  %s, %s\n", i, name.last, name.first );
  }

  freeArray( perf, array );

  printf( "reads:   %5d\n", perf->reads );
  printf( "writes:  %5d\n", perf->writes );
  printf( "mallocs: %5d\n", perf->mallocs );
  printf( "frees:   %5d\n", perf->frees );

  free( perf );
}