Storing user input whilst still asking questions - c

Question

Firstly, i know the source code below is long and you're not really supposed to post code like this, but i really don't understand why it's not working or how i could explain my issue without posting it like this.
Im trying to store the answer to each of the questions asked in it and display them at the end of the script. The biggest problem im having is that i get the error
"subscripted value is neither array nor pointer nor vector scanf("%s", a[i].incdest);"
The program doesn't accept a[i].incdest. it does this for all of the array values.
it is also saying that in function main variable "comp1" is undeclared.
#include<stdio.h>
#include<string.h>
int c_s(char*, char*);
typedef struct
{
char constab[30];
char vicwit[15];
char witdet[200];
char incdest[300];
char comp1[15];
char comp2[200];;
} sheetstore;
#define ARRAYLEN 2
sheetstore a[ARRAYLEN];
FILE *fp;
int main()
{
int i, a;
char wit[10] = "witness";
char yes[10] = "yes";
char comp1[10];
fp = fopen("sheetstore.dat","a+");
printf("Hate crime reporting system\n\n\n");
printf("If the crime you are reporting is an emergency,\nplease call 999, do not proceed any further with this form\n\n\n\nPlease press enter to confirm you have read the above and continue\n");
char enter = 0;
while (enter != '\r' && enter != '\n') { enter = getchar(); }
for( i=0; i<ARRAYLEN ; i++)
{
printf("Which police constabulary did the offence take place in?\n\n");
scanf("%s", a[i].constab);
printf("Are you a victim or witness of the crime?\nPlease answer victim/witness\n\n");
scanf("%s", a[i].comp1);
int res1 = (strcmp (comp1, wit));
if(res1 == 0){
printf("Please enter the details including phone number and address of any other witnesses that were present\n");
}
scanf("%s", a[i].witdet);
else{
printf("Where did the incident take place?\nIf in a house please provide the full address including postcode\n");
scanf("%s", a[i].incdest);
}
fwrite(&a[i], sizeof(a), 1, fp);
}
fclose(fp);
fopen("sheetstore.dat", "r");
for(i=0; i<ARRAYLEN; i++)
{
fread(&a[i], sizeof(a), 1, fp );
printf("Which police constabulary did the offence take place in? : %s\n", a[i].constab);
printf("Are you a victim or witness of the crime? : %s\n", a[i].comp1);
printf("Please enter the details including phone number and address of any other witnesses that were present : %s\n", a[i].witdet);
printf("Where did the incident take place? : %s\n", a[i].incdest);
}
fclose(fp);
return 0;
}

Answer 1

the main issue that i saw in your code, is that you shadowed the array a (sheetstore a[ARRAYLEN];) by declaring an int with the same name in your main().
you also had a scanf stament mislocated.
i fixed your code and put in a comment for every change - now, i don't persume to check the functionality of your code but at least this will compile and hopefully will give you a better understanding where you were wrong - from here it is up to you:
#include<stdio.h>
#include<string.h>
int c_s(char*, char*);
typedef struct
{
char constab[30];
char vicwit[15];
char witdet[200];
char incdest[300];
char comp1[15];
char comp2[200];;
} sheetstore;
#define ARRAYLEN 2
sheetstore sheetArr[ARRAYLEN]; //change this 'a' to avoid shadowing by the decleration on 'int a' in main
FILE *fp;
int main()
{
int i, a;
char wit[10] = "witness";
char yes[10] = "yes";
char comp1[10];
fp = fopen("sheetstore.dat","a+");
printf("Hate crime reporting system\n\n\n");
printf("If the crime you are reporting is an emergency,\nplease call 999, do not proceed any further with this form\n\n\n\nPlease press enter to confirm you have read the above and continue\n");
char enter = 0;
while (enter != '\r' && enter != '\n') { enter = getchar(); }
for( i=0; i<ARRAYLEN ; i++)
{
printf("Which police constabulary did the offence take place in?\n\n");
scanf("%s", sheetArr[i].constab);//change name from 'a'
printf("Are you a victim or witness of the crime?\nPlease answer victim/witness\n\n");
scanf("%s", sheetArr[i].comp1);//change name from 'a'
int res1 = (strcmp (sheetArr[i].comp1, wit));//compare with the value set in the struct
if(res1 == 0){
printf("Please enter the details including phone number and address of any other witnesses that were present\n");
/*this scanf should be inside the brackets of 'if(res1 == 0)' */
scanf("%s", sheetArr[i].witdet);//change name from 'a'
}
else{
printf("Where did the incident take place?\nIf in a house please provide the full address including postcode\n");
scanf("%s", sheetArr[i].incdest);//change name from 'a'
}
fwrite(&sheetArr[i], sizeof(sheetstore), 1, fp);//write a single struct
}
fclose(fp);
fopen("sheetstore.dat", "r");
for(i=0; i<ARRAYLEN; i++)
{
fread(&sheetArr[i], sizeof(sheetstore), 1, fp );//read a single struct
printf("Which police constabulary did the offence take place in? : %s\n", sheetArr[i].constab);
printf("Are you a victim or witness of the crime? : %s\n", sheetArr[i].comp1);
printf("Please enter the details including phone number and address of any other witnesses that were present : %s\n", sheetArr[i].witdet);
printf("Where did the incident take place? : %s\n", sheetArr[i].incdest);
}
fclose(fp);
return 0;
}

Answer 2

In addition to some useful comments posted above (meaningful variable names, line width not to be too long for readability), in general sense, your problem is due to two thing: in the body of the main function you declare an int a which is used instead of your global array a[ARRAYLEN]. Hence, you cannot refence a[i].incdet etc. Just comment or remove the int a from the main function. Secondly, your scanf("%s", a[i].witdet); should be in the body of the if statement above according to the program logic. I you do these two changes, the code will compile. However if you pass -Wall -Werror to the compiler, it will yields an error like error: unused variable ‘yes’ [-Werror=unused-variable]
char yes[10] = "yes";. Just comment this line to avoid using uncessary memory space on the stack.

Answer 3

The following proposed code:
corrects the first 50+ lines of your code.
Please correct your posted code so it cleanly compiles
for flexibility, separates the definition of the struct from the typedef of the struct
properly checks for error indications from system functions
honors the right margin (usually 72 or 80 characters)
replaces the CPU cycle intensive calls to printf() with calls to puts() when appropriate
This is only a guide for the first 50 lines of the OPs code. It is not a complete code replacement.
and now the proposed code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// prototypes
int c_s(char*, char*);
struct sSheet
{
char constab[30];
char vicwit[15];
char witdet[200];
char incdest[300];
char comp1[15];
char comp2[200];
};
typedef struct sSheet sheetstore;
#define ARRAYLEN 2
sheetstore a[ARRAYLEN];
FILE *fp;
int main( void )
{
int i;
char wit[10] = "witness";
//char yes[10] = "yes";
char comp1[10];
fp = fopen("sheetstore.dat","a+");
if( !fp )
{
perror( "fopen for appending to 'sheetstore.dat' failed" );
exit( EXIT_FAILURE );
}
// implied else, fopen successful
puts("Hate crime reporting system\n\n\n");
puts("If the crime you are reporting is an emergency,\n"
"please call 999, "
" do not proceed any further with this form\n\n\n\n"
"Please press enter"
" to confirm you have read the above and continue\n");
int enter = 0;
while (enter != '\r' && enter != '\n')
{
enter = getchar();
}
for( i=0; i<ARRAYLEN ; i++)
{
puts("Which police constabulary did the offence take place in?\n\n");
if( scanf("%29s", a[i].constab) != 1)
{
fprintf( stderr, "scanf for which police constabulary failed" );
fclose( fp ); // cleanup
exit( EXIT_FAILURE );
}
// implied else, scanf successful