Question

C programming


The program will require the following structure:

struct _data {                                 
   char *name;
   long number;
};

The program will require command line arguments:

int main(int argv, char **argc) {
        
Where argv is the number of arguments and argc is an array
holding the arguments (each is a string). Your program must catch 
any case where no command line arguement was provided and print
a warning message (see below).

You MUST include/use the following functions, defined as follows:

int SCAN(FILE *(*stream)) - this function will open the file/stream 
and return an integer indicating how many lines there are. Note that
I need to pass stream, which is a pointer, by reference. So I am 
passing this as a pointer to a pointer.

struct _data *LOAD(FILE *stream, int size) - this function will 
rewind file, create the dynamic array (of size), and read in the 
data, populating the _data struct dynamic array. Note that stream 
is passed by value this time. The function then returns the populated 
array of struct.

void SEARCH(struct _data *BlackBox, char *name, int size) - this function
will get the dynamic array of struct passed to it, the name we are looking
for, and the size of the array. This function will then search the dynamic
array for the name. See below for examples.

void FREE(struct _data *BlackBox, int size) - this function will free up
all of the dynamic memory we allocated. Take note of the number of times 
malloc/calloc were called, as you need to free that same number.

Finally, the data file will be called hw5.data and will beformated as:

ron 7774013
jon 7774014
tom 7774015
won 7774016

HINTS:
------
Functions that will make things much easier:
getline()
feof()
strtok()
atoi()

* Make sure you read the man pages for each. They have some "gotchas".

SAMPLE RUNS:
------------
Case 1 - No command line argument provided.

[rmarsh@chef junk]$ ./CS230-5
*******************************************
* You must include a name to search for.  *
*******************************************

Case 2 - Provided name is NOT in the list.

[rmarsh@chef junk]$ ./CS230-5 joe
*******************************************
The name was NOT found.
*******************************************

Case 3 - Provided name is in the list.

[rmarsh@chef junk]$ ./CS230-5 tom
*******************************************
The name was found at the 2 entry.
*******************************************

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct _data {
   char *name;
   long number;
};
int SCAN(FILE *(*stream)) {
    int lines = 0;
    (*stream) = fopen("/home/ramkumar/Study/Chegg/1115.txt","r"); // read mode
    if( (*stream) == NULL )
    {
          perror("Error while opening the file.\n");
          return 0;
    }
    while(!feof((*stream)))
    {
      int ch = fgetc((*stream));
      if(ch == '\n')
      {
        lines++;
      }
    }
    rewind(*stream);
    return lines;
}
struct _data *LOAD(FILE *stream, int size){
    char line[256] = {'\0'};
   struct _data * items = (struct _data *)malloc(size*(sizeof(struct _data)));
   int index = 0;;
   while (fgets(line, sizeof(line), stream) != NULL){
       index++;
       if(index == size){
           break;
       }
       //Break each line by spaces
       char * name = strtok(line," ");
       //get name
       int nameLenght = strlen(name);
       struct _data * item = (items + index);
       item->name = (char *) malloc(nameLenght+1);
       memset(item->name,'\0',nameLenght+1);
       strcpy(item->name,name);

       //get number
       item->number = atol(line+nameLenght+1);

   }
   return items;
}
void SEARCH(struct _data *BlackBox, char *name, int size) {
    for(int i = 0 ; i < size ; i++){

        if( strcmp( (BlackBox + i)->name,name) == 0){
            printf("he name was found at the %d entry.", (i+1));
            return;
        }
    }
    printf("The name was NOT found.");
}
void FREE(struct _data *BlackBox, int size) {
    for(int i = 0 ; i < size ; i++){
        struct _data * item = (BlackBox + i);
        //Free Name String
        free (item->name);
        //Free item
        free(item);
    }
}

int main(int argc, char *argv[])
{
    if(argc ==0){
        printf("* You must include a name to search for. *");
        return 0;
    }
    FILE * fp;
    SCAN(&fp);
    struct _data * items = LOAD(fp,4);
    SEARCH(items,argv[0],4);
    FREE(items,4);
    return 0;
}