about using data in structure from a text file

[MyRedz]

how can this be done? do i have to pointer the database in the structure first to make it able to be use from a text file for some C program ..example..
a measurement converter??

[Sci@phy]

I (and presumably lots of people) don't understand your question at all.
Maybe providing us with some example of what you want to do or something

[ahamed101]

What is your problem anyways... No clue... seriously... one thing we know, you got a problem for sure... be more specific buddy...

[MyRedz]

welll sorry for it..
i need to figure how it's done...
this is a program that takes a measurement in one unit (e.g., 4.5 miles, etc) and converts it to another unit (i.e. kilometers).
the algorithm is
The algorithm for the program is fairly straightforward.
1
. Load units of measurement database.
2.
Get value to convert and old and new unit names.
3.
Repeat until data format error encountered.
4.
Search for old unit in database.
5.
Search for new units in database.
6.
If conversion is impossible, issue appropriate message,
7.
Else, compute and display conversion
8.
Get value to convert an old and new unit names..

and then the unit.dat
is

kilometers km distance 1000
yards yd distance 0.9144
meters m distance 1
quarts qt volume 0.94635
liters l volume 1
gallons gal volume 3.7854
milliliters ml volume 0.001
kilograms kg mass 1
grams g mass 0.001
slugs slugs mass 0.14594
 my code is this
i

well how to search and display the error when have found the target??any ideas??

#include <stdio.h>
void calculate conversion(double input)
char input_oldunit;
double input_value;
char input_newunit;
struct unit
4{
char oldunit[12];
char SI	[5];
char newunit[10];
double value;
};

int main()
{
	struct unit h[20];
        int k = 0.0;
        char choice


FILE *measurement;
	
	printf("\THIS IS A UNIVERSAL MEASUREMENT PROGRAMn");
	
measurement = fopen("unit.dat","r");
	do{
printf("\nPlease select q to quit or other to enter conversion program:");
	scanf("%s",&choice);
	printf("You have selected option %d\n\n",choice);
	switch(choice)
	{


case q:

printf("thank s and have a nice day\n);

return 0;
break;
}
default:{
	

	if (measurement == NULL)
		printf("Error opening data file.\n");
	else
	{
		while(fscanf(measurement,"%s %s %s %lf ",&h1[k].oldunit,&h1[k].SI,&h1[k].newunit,&h1[k].value)==4)
		{
                       printf(" input your values followed with it's measurement name or SI unit and the target measurement's name or SI unit.\n");
                       scanf(" %lf %s %s",&input_value,&input_oldunit,&input_newunit);
			calculate conversion(input);
}


		}

		
		
	
	}

fclose(measurement);
}
	printf("If you want to quit, press q or else press any key to continue\n");
	scanf("%s",&choice);
	}while(optn!=q);
	printf("To the infinite..and BEYOND....!!!!!\n\n");
break;
return;
}

any ideas on the repeat data format until error found???
i have no idea...so and search for old and new units..

[ahamed101]

welll sorry for it..
i need to figure how it's done...
this is a program that takes a measurement in one unit (e.g., 4.5 miles, etc) and converts it to another unit (i.e. kilometers).
the algorithm is
The algorithm for the program is fairly straightforward.
1
. Load units of measurement database.
2.
Get value to convert and old and new unit names.
3.
Repeat until data format error encountered.
4.
Search for old unit in database.
5.
Search for new units in database.
6.
If conversion is impossible, issue appropriate message,
7.
Else, compute and display conversion
8.
Get value to convert an old and new unit names..

and then the unit.dat
is

kilometers km distance 1000
yards yd distance 0.9144
meters m distance 1
quarts qt volume 0.94635
liters l volume 1
gallons gal volume 3.7854
milliliters ml volume 0.001
kilograms kg mass 1
grams g mass 0.001
slugs slugs mass 0.14594
 my code is this
i

well how to search and display the error when have found the target??any ideas??

any ideas on the repeat data format until error found???
i have no idea...so and search for old and new units..

The code you have posted is full of syntax errors... correct it...
Meanwhile...
For repeating your code until the error is encountered you may use do-while or simple while or something like that...
For loading the database and searching it- you can do it in either
1) when ever the user enters the data, search the file without actually loading it anywhere... read line by line and search...
2) you can load the whole text file into an array(probably loading it into an array structure would be better) for once and then search it whenever user enters the data...

[MyRedz]

For loading the database and searching it- you can do it in either
1) when ever the user enters the data, search the file without actually loading it anywhere... read line by line and search...
...this is very good..
but any examples...i think i want to use it....

[ahamed101]

You can use fgets, check this... there is an example at the end...

[MyRedz]

well here we go..

well here goes my coding..any way to improve it?
i done with the unit.dat file which contains
measurement ,abbreviation, classes and it's value.
i use linear search...
any methods to make it more neat,tidy..?
anyway there are some errors that i tried but couldn't correct it..
is it possible to make the fscanf simple without the function prototype???

#include<stdio.h>
#include<string.h>
#define  NOT_FOUND  -1
typedef struct 
{
    char name[30];
    char abbrev[15];
    char class[20];
    double standard;
} unit_t

int fscan_unit(FILE *filep,unit_t *unitp){
    int status;
    status = fscanf(filep, "%s%s%s%lf",(*unitp).name,(*unitp).abbrev,(*unitp).class,&(*unitp).standard);
    if(status == 4)
        status = 1;
    else if (status != EOF)
        status = 0;

    return (status);
}

void
load_units(int      unit_max,
           unit_t   units[],
           int     *unit_sizep)

{
    FILE  *inp;
    unit_t data;
    int    i, status;

    inp = fopen("units.dat","r");
    i = 0;

    for (status = fscan_unit(inp, &data);
         status == 1  &&  i < unit_max;
         status = fscan_unit(inp, &data)) {
       units[i++] = data;
    }
    fclose(inp);
    if (status == 0) {
          printf("\n*** Error in data format ***\n");
          printf("*** Using first &d data format ***\n");
    } else if (status != EOF) {
          printf("\n*** Error: too much data in file ***\n");
          printf("*** Using first %d data values ***\n", i);
    }

    *unit_sizep = i;
 }



 int
 search(const unit_t units[],
        const char  *target,
        int         n)

{
        int i,
            found = 0,
            where;

        i = 0;
        while (!found && i < n) {
            if (strcmp(units[i].name,   target) == 0 ||
                strcmp(units[i].abbrev, target) == 0)
                   found = 1;
            else
            ++i;
         }
if(found)
where = i;
else 
 where = NOT_FOUND;
return(where);

}
double convert(double quantity,double old_stand, double new_stand)
{

  return(quantity*old_stand/new_stand);

}




int main(void)

{


 unit_t units[20];

int num_units;
char old_units[30],new_units[30];
int status;
double quantity;

int old_index,new_index;

load_units(20,units,&num_units);

printf("Enter a conversion problem or q to quit.\n");
printf("To convert 25 kilometers to miles,you would enter\n");
printf(">25 kilometers miles\n");
printf("       or,alternatively,\n");
printf(">25 km mi\n>");

for(status = scanf("%lf %s%s",&quantity,&old_units,&new_units);
status == 3;
status = scanf("%lf %s%s",&quantity,&old_units,&new_units)){
printf("attempting conversion of %.4e %s to %s ...\n",quantity,&old_units,&new_units);
old_index = search(units,old_units,num_units);
new_index = search(units,old_units,num_units);
if (old_index == NOT_FOUND){
printf("Unit %s not in database\n",old_units);
}
else if (new_index == NOT_FOUND){
printf("UNit %s not in database\n",new_units);
}
else if (strcmp(units[old_index].class,units[new_index].class)!=0)
else 
printf(" Cannot convert %s(%s) to %s (%s)\n",old_units,units[old_index].class,new_units,units[new_index].class);
else
printf("%.4e %s = %.4e %s\n",quantity,old_units,convert(quantity,units[old_index].standard,units[new_index].standard),new_index);

printf("\nEnter a conversion problem or q to quit\n");
}
return(0);
}

my new one..can i replace fgets in the
linear search function???