What I am trying to do:
Make a program that opens a file and read the content (mostly characters)
Example on what it should do:
The file contains "ABA", It should print: Letter A Count 2 || Letter B Count 1
but I am getting this error when I start debugging http://imgur.com/a/zvpWg
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <ctype.h>
struct arr
{
char letter;
int count;
};
void main ()
{
arr s[7];
char letter;
FILE *fp;
fp=fopen("D:\\data.txt","r");
if(fp==NULL)
{
printf("Error File Not Found\n");
getch();
exit(1);
}
while(fscanf(fp,"%ch",&letter)!=EOF)
{
for(int i=0;i<7;i++)
{
if(!isalpha(s[i].letter))
{
s[i].letter=letter;
s[i].count=1;
break;
}
else if(s[i].letter == letter)
s[i].count++;
break;
}
}
for(int h=0;h<7;h++)
printf("Letter: %c Count: %d ||",s[h].letter,s[h].count);
getch();
}
Where am i wrong exactly ?
The Problem might be -
function isalpha() is being called with an integer whose value is not a single byte i.e. 0-255.
Related
I'm trying to write a program that asks for input of the name of a file and a char to be counted inside the file. But whenever I input the proper name of a file (like, "file.txt") it jumps right to the end of the program with a output like this:
"Name of the file: file.txt
Character to be counted:
The char occurs 0 times in the file "
...but I couldn't even type the char to be counted.
I know it's not an issue with the name of the file, because if I put the wrong name, it goes for the output I programmed for.
Would anyone care to explain me what's happening?
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void) {
char filename[128];
printf("Name of the file: ");
scanf("%s", filename);
FILE * test = fopen(filename, "r");
if (test == NULL) {
printf("Error!!\n");
exit(1);
}
char inpt;
printf("Character to be counted:\n");
scanf("%c", &inpt); //gets the character to be counted
int count = 0;
char search = fgetc(test);
while(search != EOF) {
if (search == inpt) count++;
search = fgetc(test);
}
printf("The char occurs %d times in the file\n", count);
return 0;
}
How do I put isalpha and isdigit in a while(1) loop?
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
int main()
{
int i;
char type[256];
printf("You can type a number or a word. Type exit to exit! \n");
printf("Type: ");
fgets (type, 256, stdin);
if (isalpha(type[i]))
{
printf("Typed text: %s\n", type);
if((strcmp(type,"exit\n") == 0))
{
printf("Exiting...\n");
exit(1);
}
}
else if (isdigit(type[i]))
{
printf("Typed number: %s\n", type);
}
else
{
printf("Typed: %s\n", type);
printf("Its not a letter or number...?!\n");
}
}
I tried adding while(1) at the start at the code and close it at the end of code, but as soon as I enter number or letter the console crashes... Could someone please help me with this?
Your problem is not a loop problem, you need to give a value to i , as it is undefined and you get a nice crash. Please replace
int i;
with
int i=0;
I'm new to this forum and would like to seek help. I'm trying to modify an anagram program based on code from http://www.sanfoundry.com/c-program-...ings-anagrams/.
This time, however, I have used array pointers to obtain input from the user. I have also created a function "check_input" to ensure that the input consists of ONLY characters and excludes symbols(!, #, $). However, when I ran the program, it still accepts those symbols and does not break like I wanted it to. Please help.
Plus, I intend to make the program treat upper-case letters the same way as lower-case letters. Can this be achieved by using the "stricmp" function? If so, where should I place that function? Alternative methods are also appreciated.
Update: Sorry. I've added the check_input code at the bottom.
#include <stdio.h>
#include <ctype.h>
#include <string.h>
int test_anagram(char *ptrArray1, char *ptrArray2);
int check_input(char array1[], char array2[]);
int main()
{
char array1[100], array2[100];
char *pArray1, *pArray2;
int flag;
pArray1 = array1;
pArray2 = array2;
printf("Enter the first word: \n");
gets(pArray1);
printf("Enter the second word: \n");
gets(pArray2);
check_input(pArray1, pArray2);
flag = test_anagram(pArray1, pArray2);
if(flag == 1){
printf("\"%s\" and \"%s\" are anagrams.\n", pArray1, pArray2);
}else{
printf("\"%s\" and \"%s\" are not anagrams.\n", pArray1, pArray2);
}
return 0;
}
int test_anagram(char array1[], char array2[])
{
int num1[26] = {0}, num2[26] = {0}, i = 0;
while(array1[i] != '\0')
{
num1[array1[i] - 'a']++;
i++;
}
i = 0;
while(array2[i] != '\0')
{
num2[array2[i] - 'a']++;
i++;
}
for(i=0;i<26;i++)
{
if(num1[i] != num2[i]){
return 0;
}
return 1;
}
}
int check_input(char array1[], char array2[])
{
while(isalpha((int)array1) != 1){
break;
}
while(isalpha((int)array2) != 1){
break;
}
}
You haven't (yet) posted the full code of the check_input() function but one advice would be to validate the input when the user inputs every character.
You can do this using f.e. the getchar() function and checking if the inputted character is a letter, as well as converting it to the lowercase (or uppercase if you will).
You can do lowercase convertion like this:
#include <ctype.h>
// ...
tolower('A');
The following code reads from a file the occurrences of the digit 1. My question is how could such an occurrence be replaced with another number (say '4') and written back again in the file. The while loop will be continued with?
int next;
FILE *f;
if (!(f=fopen("C:\\Test\\Sign.txt", "rt")))
{
printf("File not existing\n");
}
else{
while((next=='1')!=EOF)
The proper solution for that [including the initial one] would be:
#include <stdio.h>
#include <conio.h>
int f(FILE *);
int main(){
int num=0, next;
FILE *f;
if (!(f=fopen("C:\\Test\\Sign.txt", "rt")))
{
printf("File not existing\n");
}
else{
for(;;){
if((next=fgetc(f))== EOF) break;
if (next == '1') num++;}
}
printf("Found occurrences of digit 1 are %d\n", num);
getch();
}
The for loop counts the occurrences of ones[in this case] whenever it passes through the number with fgetc assigned to the value of next which is 1.
input value 123 -- this value is integer, and valid
input value 1b23a -- this value is invalid
How do I detect which values are valid and not?
Here is my code:
#include <stdio.h>
#include <conio.h>
void main()
{
char str1[5],str2[5];
int num,num1,i;
num=0;
clrscr();
printf("Enter the Number ");
scanf("%s",str1);
for(i=0;str1[i]!='\0';i++)
{
if(str1[i]>=48&&str1[i]<=56)
num=num1*10+(str[i]-48);
else
{
printf("The value is invalid ");
}
}
printf("This Number is %d",num);
getch();
}
Please see this answer regarding use of strtol(). It is a safe way to convert arbitrary input that should be a string representation of an integer, while also saving 'garbage' bytes for additional analysis.
Using it, your code would look something like this:
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#ifdef LINUX_VERSION
#include <curses.h>
#else
#include <conio.h>
#endif
#define BUFF_SIZE 1024
int main(void)
{
char str1[BUFF_SIZE], *garbage = NULL;
long num = 0;
printf("Enter the Number ");
scanf("%s",str1);
errno = 0;
num = strtol(str1, &garbage, 0);
if (errno) {
printf("The number is invalid\n");
return 1;
}
printf("You entered the number %ld\n", num);
if (garbage != NULL) {
printf("Additional garbage that was ignored is '%s'\n", garbage);
}
getch();
return 0;
}
This doesn't fix everything that is questionable about what you posted, but it should help you get off to a better start.
Output is:
tpost#tpost-desktop:~$ ./t
Enter the Number 1234abdc
You entered the number 1234
Additional garbage that was ignored is 'abdc'
Compiled via:
gcc -Wall -DLINUX_VERSION -o t t.c -lcurses
I'm not sure what platform you are using, so additional fixes to the code may be needed.
#include<stdio.h>
#include<conio.h>
void main()
{
char str1[5],str2[5];
int num,num1,i;
num=0;
clrscr();
printf("Enter the Number ");
scanf("%s",str1);
for(i=0;str1[i]!='\0';i++)
if(str1[i]>=48&&str1[i]<=56)
num=num1*10+(str[i]-48);
else
{
printf("The value is invalid ");
}
}
printf("This Number is %d",num);
getch();
}
One way is to use sscanf and check that there are no characters following the number. This is done most easily by adding a %c on the end and testing the return code, like this:
const char *yourString = ...;
int theValue, dummy;
if (sscanf(yourString, "%d%c", &theValue, &dummy) == 1) {
// Was a pure number, parsed into 'theValue'
} else {
// Either no number or had junk after it
}