Currently I am making a project that uses char arrays that have null elements. I want to be able to get the length of the array, in the sense of the number of elements that aren't null. This seemed reasonably trivial and I made this function:
int getWordLen(char word[]) {
int count = 0;
for (int i = 0; i < 512; i++) {
if (word[i] != '\0') {
count++;
}
}
printf("%d ", count);
return count;
}
However, every char array returns a length of 188. Any help would be appreciated.
This is the function I was calling it from:
void redact(Words * redactWords, char fileName[]) {
FILE * file = fopen(fileName, "r");
FILE * outputFile = fopen("outputFile.txt", "w+");
char word[512];
int i = 0;
char c;
while (c != EOF) {
c = getc(file);
if ((c > 96) && (c < 123)) {
word[i] = c;
i++;
continue;
}
else if ((c > 64) && (c < 91)) {
word[i] = c + 32;
i++;
continue;
}
i = 0;
if (isWordRedactWord(redactWords, word)) {
//write stars to file
char starStr[512];
for (int i = 0; i < getWordLen(word); i++) {
starStr[i] = '*';
}
fputs(starStr, outputFile);
}
else {
//write word to file
fputs(word, outputFile);
}
strcpy(word, emptyWord(word));
}
fclose(file);
fclose(outputFile);
}
In the initial while, I would only use while(!EOF).
Also, I believe you are using a lot more resources than necessary with the implementation of that for inside the while:
char starStr[512];
for (int i = 0; i < getWordLen(word); i++) {
starStr[i] = '*';
I suggest you to put it outside the while loop and see what happens.
If it is always giving you 188 of lenght, it is counting something that's constant, and may be related to that outer loop.
Hope you can solve it!
Related
I have a program, which receives filename as an input, saves file contents into 2d char array and then outputs words. It works absolutely fine for about 400 words, but then, when I add more words, it crashes. Debugging showed that i am trying to access unused address, and I don't understand how is that possible considering that previous tests with lesser amount of words were successful.
The question is: what am i missing here?
FILE: functions.c
#include "Lab10.h"
#include <stdio.h>
#include <malloc.h>
char** parser(char* filename) {
FILE* fp;
fp = fopen(filename, "r");
char** str = (char**)calloc(N, sizeof(char*) * N);
if (!str)
{
printf("\n Allocation error");
return NULL;
}
char ch;
int space = 0, words = 0;
for (int i = 0; !feof(fp); i++) // Memory allocation
{
ch = fgetc(fp);
if (!is_ch(ch))
{
if (i != space)
{
if (!(str[words] = (char*)calloc(i - space, sizeof(char) * (i - space))))
{
printf("\n Allocation error");
return NULL;
}
words++;
}
while (!is_ch(ch) && !feof(fp))
{
ch = fgetc(fp);
i++;
}
if(!feof(fp))
fseek(fp, -(int)sizeof(char), 1);
i--;
space = i;
}
}
fseek(fp, 0, SEEK_SET);
for (int i = 0; i < words; i++) // Copying words into 2d array
{
while (!is_ch(fgetc(fp)));
if (!feof(fp))
fseek(fp, -(int)sizeof(char), 1);
int j = 0;
do {
if (((fscanf(fp, "%c", &str[i][j])) != 1))
break;
j++;
} while (is_ch(str[i][j-1]) && !feof(fp));
}
return str;
}
int is_ch(char ch)
{
return ((ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'));
}
FILE: main.c
#define _CRT_SECURE_NO_WARNINGS
#include "Lab10.h"
#include <stdio.h>
#include <stdlib.h>
int main() {
char* filename = (char*)malloc(sizeof(char) * N);
if (!scanf("%s", filename) || filename == 0)
{
printf("\n Incorrect filename input");
return -1;
}
char** str = parser(filename);
printf("\n Contents of .txt file:");
for (int i = 0; str[i] != NULL; i++) {
printf("\n\t%d) ", i+1);
for (int j = 0; is_ch(str[i][j]); j++) {
printf("%c", str[i][j]);
}
}
return 0;
}
This answer was posted as a reply to one of the comments below the question itself. I tried writing readWord function, which recieves filepointer, reads one word and then returns pointer to the resulting array - that's eases the procedure, making it less complex. It works almost like fgets(), but it reads till non-character, instead of a newline
readWord function itself:
char* readWord(FILE* fp) {
char ch = 0;
while (!is_ch(ch))
{
ch = fgetc(fp);
if (ch == EOF || !ch)
return NULL;
}
int size = 1;
while (is_ch(ch))
{
if ((ch = fgetc(fp)) == EOF || !ch)
break;
size++;
}
fseek(fp, -(size * (int)sizeof(char)), 1);
if (ch != EOF || !ch)
size--;
char* word = (char*)calloc(size, sizeof(char) * size + 1);
if (!word)
{
printf("\n Allocation error.");
return NULL;
}
for (int i = 0; i < size; i++)
word[i] = fgetc(fp);
word[size] = '\0';
return word;
}
That's how i use it in main():
FILE* fp = fopen("test.txt", "r");
char* word;
while ((word = readWord(fp)) != NULL)
{
for (int i = 0; word[i] != '\0'; i++)
printf("%c", word[i]);
printf(" ");
}
Is there is anything i need to improve here? It works fine, but is it possible to somehow make it better?
I want to count the number of words that are in a file. I store each line of the text in the file using a double pointer and then manipulate it do other things.
char **create2DArray()
{
int i = 0;
char **str = malloc(sizeof(char *) * 100);
for (i = 0; i < 100; i++)
{
str[i] = malloc(sizeof(char) * 1000);
}
return str;
}
char **readFile(char **str)
{
int i = 0;
FILE *pFile;
char *filename = "C:\\Users\\muham\\OneDrive\\Documents\\A2\\A2 Samples\\sample1.txt";
pFile = fopen(filename, "r");
if (pFile == NULL)
{
printf("Could not open file");
exit(1);
}
while (fgets(str[i], 1000, pFile) != NULL)
{
RemoveReturn(str[i]);
lineCount++;
printf("%s\n", str[i]);
i++;
}
fclose(pFile);
return str;
}
int wordCount(char **str)
{
int wordCounting = 0;
int i = 0;
int q = 0;
for (i = 0; i < lineCount; i++)
{
for (q = 0; q <= strlen(str[i]); q++)
{
if (*str[q] == ' ' || *str[q] == '\0')
{
wordCounting++;
}
if (*str[q] == ' ' && *str[q + 1] == ' ' && *str[0] != ' ')
{
wordCounting--;
}
if (*str[0] == ' ')
{
wordCounting--;
}
if (*str[q] == ' ' && *str[q + 1] == '\0')
{
wordCounting--;
}
if (strlen(str[q]) == 0)
{
wordCounting--;
}
}
}
printf("%d\n", wordCounting);
return wordCounting;
}
As of right now, when I run the program, wordCount prints 0. Why is this happening? Is it because I am iterating through the number of pointers with str[i] and not the strings stored in str[i]? How do I fix this?
There are several issues in your code; The most obvious one is probably your loop for (i = 0; i <= strlen(str[i]); i++), in which you compare the length of the ith string with the value of i, and you use the same i then to access the characters of the ith string. This all rarely makes sense.
I'd start with two things:
First, make sure that you do not access uninitialized rows, i.e. consider lineCount. A simple way would be to make it either a global variable or to return it in readFile; signature would change to int readFile(char **str) { ....; return lineCount; }
Second, use two nested loops:
for (int line=0; line<lineCount; line++) {
for (int column=0; column < strlen(str[line]); column++) {
// your code for detecting lines goes here...
}
}
I have created a program that reads a series of strings from a .txt file and after compiling a new .txt file is created where the strings should be in alphabetical order.The problem is that I can't write more than 10 words, the compiler just stops/crashes, WHY? Does it depend by the type of compiler? I am currently using Code-Bloks.How can I optimize the code to run more smoothly?
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
void arrange(int n, char *x[])
{
char *temp;
int i,str;
for(str = 0; str < n-1; ++str)
{
for(i = str+1; i < n; ++i)
{
if(strcmp(x[str],x[i]) > 0)
{
temp = x[str];
x[str] = x[i];
x[i] = temp;
}
}
}
return;
}
int number_of_lines = 0;
void countOfLinesFromFile(char *filename){
FILE* myfile = fopen(filename, "r");
int ch;
do
{
ch = fgetc(myfile);
if(ch == '\n')
number_of_lines++;
}
while (ch != EOF);
if(ch != '\n' && number_of_lines != 0)
number_of_lines++;
fclose(myfile);
return number_of_lines;
}
int main()
{
int i , ts=0;
char *x[10];
char *fileName = "WORDS.txt";
countOfLinesFromFile(fileName);
printf("%d",number_of_lines);
FILE * fp;
fp = fopen ("WORDS.txt", "r");
for(i = 0; i < number_of_lines; i++)
{
x[i] = (char*) malloc (1200*sizeof(char));
fscanf(fp, "%s", x[i]);
}
FILE *fPointer;
fPointer=fopen("Alphabetical.txt","w+");
arrange(i,x);
for(i = 0; i < number_of_lines; i++)
{
fprintf(fPointer,"%s\n",x[i]);
}
fclose(fPointer);
fclose(fp);
return 0;
}
char *x[10];
The buffer size is too small
These two lines define how much information you can store
char *x[10]; // 10 strings
x[i] = (char*) malloc (1200*sizeof(char)); // 1200 characters each
As it is written now, you can only hold a maximum of 10 strings with each string being no longer than 1200 characters.
The crash is caused when number_of_lines >= 11 in the following for loop:
for(i = 0; i < number_of_lines; i++)
{
x[i] = (char*) malloc (1200*sizeof(char));
fscanf(fp, "%s", x[i]);
}
When i is 11 you write to x[11] which is past the end of x.
I wrote this code which reads every char of my text and puts it into my char array. My Problem is that the end of the file is not detected and so the fscanf() returns after the end of the text every time the last char until my array is filled. How can I prevent that? I am programming in C.
My Code:
int main() {
char array[50][50];
char buff;
FILE *cola = fopen("C:/Users/danie/Desktop/cola.txt", "r");
for (int i = 0; i < 50; i++) {
for (int k = 0; k < 50; k++) {
fscanf(cola, "%c", &buff);
array[i][k] = buff;
}
}
fclose(cola);
for (int i = 0; i < 50; i++) {
for (int k = 0; k < 50; k++) {
printf("%c", array[i][k]);
}
}
return 0;
}
Thank you for your help.
fscanf() returns the number of successful conversions. You should test the return value and also handle newline characters specifically:
#include <stdio.h>
int main(void) {
char array[50][50];
char buff;
FILE *cola = fopen("C:/Users/danie/Desktop/cola.txt", "r");
if (cola == NULL) {
return 1;
}
for (int i = 0; i < 50; i++) {
for (int k = 0; k < 50; k++) {
if (fscanf(cola, "%c", &buff) != 1 || buff == '\n') {
array[i][k] = '\0';
break;
}
array[i][k] = buff;
}
}
fclose(cola);
for (int i = 0; i < 50; i++) {
for (int k = 0; k < 50 && array[i][k] != '\0'; k++) {
printf("%c", array[i][k]);
}
printf("\n");
}
return 0;
}
The code can be simplified if you use getc() instead of fscanf() to read bytes from the file:
#include <stdio.h>
int main(void) {
char array[50][51];
int c, i, k, n;
FILE *cola = fopen("C:/Users/danie/Desktop/cola.txt", "r");
if (cola == NULL) {
return 1;
}
for (n = 0; n < 50; n++) {
for (k = 0; k < 50; k++) {
if ((c = getc(cola)) == EOF || c == '\n') {
break;
}
array[n][k] = c;
}
array[n][k] = '\0';
if (c == EOF && k == 0)
break;
}
fclose(cola);
for (i = 0; i < n; i++) {
puts(array[i]);
}
return 0;
}
Replace:
for (int i = 0; i < 50; i++) {
for (int k = 0; k < 50; k++) {
fscanf(cola, "%c", &buff);
array[i][k] = buff;
}
}
with:
for (int i = 0; i < 50; i++) {
for (int k = 0; k < 50; k++) {
int c = getc(cola);
if (c == EOF)
break;
array[i][k] = c;
}
}
Since buff is then unused, don't define it. Note that the return type of getc() is an int, not just a char. Always check the I/O function for success/failure. In your original code, you don't even check whether the I/O operation succeeds, which makes detecting EOF impossible.
Note that this code makes a number of assumptions that may or may not be justifiable. For example, you assume each line in the file consists of 49 characters plus a newline; you also assume you'll never need to print the information as a 'string' (your existing code does not; it prints character by character, so it is 'safe').
You might want to describe the input as:
Read up to 50 lines with up to 49 characters plus a newline in each line, storing the result in the variable array with each line being a null-terminated string.
This is more resilient to common problems (short lines, long lines, not enough lines). The code for that might be:
enum { LINE_LEN = 50, NUM_LINES = 50 };
char array[NUM_LINES][LINE_LEN];
int i;
for (i = 0; i < LINE_LEN; i++)
{
int c;
int k;
for (k = 0; k < LINE_LEN; k++)
{
c = getc(cola);
if (c == EOF || c == '\n')
break;
if (k == LINE_LEN - 1)
{
/* Too long - gobble excess */
while ((c = getc(cola)) != EOF && c != '\n')
;
break;
}
array[i][k] = c;
}
array[i][k] = '\0';
if (c == EOF)
break;
}
int num_lines = i; // You have num_lines lines of data in your array
I found one version of the Coca Cola™ ASCII art image at https://www.ascii-code.com/ascii-art/logos/coca-cola.php which looks similar to what you have in your images, but there are many other sources and variants:
__ ___ __ .ama ,
,d888a ,d88888888888ba. ,88"I) d
a88']8i a88".8"8) `"8888:88 " _a8'
.d8P' PP .d8P'.8 d) "8:88:baad8P'
,d8P' ,ama, .aa, .ama.g ,mmm d8P' 8 .8' 88):888P'
,d88' d8[ "8..a8"88 ,8I"88[ I88' d88 ]IaI" d8[
a88' dP "bm8mP8'(8'.8I 8[ d88' `" .88
,88I ]8' .d'.8 88' ,8' I[ ,88P ,ama ,ama, d8[ .ama.g
[88' I8, .d' ]8, ,88B ,d8 aI (88',88"8) d8[ "8. 88 ,8I"88[
]88 `888P' `8888" "88P"8m" I88 88[ 8[ dP "bm8m88[.8I 8[
]88, _,,aaaaaa,_ I88 8" 8 ]P' .d' 88 88' ,8' I[
`888a,. ,aadd88888888888bma. )88, ,]I I8, .d' )88a8B ,d8 aI
"888888PP"' `8""""""8 "888PP' `888P' `88P"88P"8m"
This file's longest line is the first at 67 characters plus newline; the shortest is 61 characters plus newline. The file only has 13 lines and 845 characters (LF line endings) in total. Thus, your program is ill-equipped to deal with this particular data file. It looks for 2,500 characters, and won't get them.
My complete test code was rigged to read from standard input, rather than a fixed file name.
#include <stdio.h>
int main(void)
{
FILE *cola = stdin;
enum { LINE_LEN = 80, NUM_LINES = 50 };
char array[NUM_LINES][LINE_LEN];
int i; // Need value of i after loop
for (i = 0; i < NUM_LINES; i++)
{
int c; // Need value of c after loop
int k;
for (k = 0; k < LINE_LEN; k++)
{
c = getc(cola);
if (c == EOF || c == '\n')
break;
if (k == LINE_LEN - 1)
{
/* Too long - gobble excess */
while ((c = getc(cola)) != EOF && c != '\n')
;
break;
}
array[i][k] = c;
}
array[i][k] = '\0';
if (c == EOF)
break;
}
int num_lines = i; // You have num_lines lines of data in your array
for (i = 0; i < num_lines; i++)
puts(array[i]);
return 0;
}
I tested it on the data file shown, with an empty line at the end, and with a couple of lines containing more than 79 characters after the blank line. It handled all those special cases correctly. Note that handling user input is hard; handling perverse user input is harder. The code is less compact. You could change the rules and then change the code to match. I'm not sure this is the most minimal way to code this; it does work, however. It might be better to have a function to handle the inner input loop; the outer loop could test the return value from that function. This would cut down on the special case handling.
#include <assert.h>
#include <limits.h>
#include <stdio.h>
static int read_line(FILE *fp, size_t buflen, char *buffer)
{
assert(buflen < INT_MAX);
int c; // Need value of c after loop
size_t k; // Need value of k after loop
for (k = 0; k < buflen; k++)
{
if ((c = getc(fp)) == EOF || c == '\n')
break;
if (k == buflen - 1)
{
/* Too long - gobble excess */
while ((c = getc(fp)) != EOF && c != '\n')
;
break;
}
buffer[k] = c;
}
buffer[k] = '\0';
return (k == 0 && c == EOF) ? EOF : (int)k;
}
int main(void)
{
enum { LINE_LEN = 80, NUM_LINES = 50 };
char array[NUM_LINES][LINE_LEN];
int i;
for (i = 0; i < NUM_LINES; i++)
{
if (read_line(stdin, LINE_LEN, array[i]) == EOF)
break;
}
int num_lines = i;
for (i = 0; i < num_lines; i++)
puts(array[i]);
return 0;
}
This produces the same output from the same input as the previous version.
int main() {
//char array[50][50];
char buff;
int t;
FILE *cola = fopen("C:/Users/danie/Desktop/cola.txt", "r");
if (cola == NULL)
{
printf("Cannot open file \n");
exit(0);
}
while (1) {
t = fgetc(cola);
if (t == EOF)
break;
buff = t;
printf("%c", buff);
}
fclose(cola);
return 0;
}
If I have an options file along the lines of this:
size = 4
data = 1100010100110010
And I have a 2d size * size array that I want to populate the values in data into, what's the best way of doing it?
To clarify, for the example I have I'd want an array like this:
int[4][4] array = {{1,1,0,0}, {0,1,0,1}, {0,0,1,1}, {0,0,1,0}}. (Not real code but you get the idea).
Size can be really be any number though.
I'm thinking I'd have to read in the size, maloc an array and then maybe read in a string full of data then loop through each char in the data, cast it to an int and stick it in the appropriate index? But I really have no idea how to go about it, have been searching for a while with no luck.
Any help would be cool! :)
int process_file(int **array, char const *file_name)
{
int size = 0;
FILE *file = fopen(file_name, "rt");
if(fp == null)
return -1;//can't open file
char line[1024]; //1024 just for example
if(fgets(line, 1024, file) != 0)
{
if(strncmp(line, "size = ", 7) != 0)
{
fcloes(file);
return -2; //incorrect format
}
size = atoi(line + 7);
array = new int * [size];
for(int i = 0; i < size; ++i)
array[i] = new int [size];
}
else
{
fclose(file);
return -2;//incorrect format
}
if(fgets(line, 1024, file) != 0)
{
if(strncmp(line, "data = ", 7) != 0)
{
fcloes(file);
for(int i = 0; i < size; ++i)
delete [] array[i];
delete [] array;
return -2; //incorrect format
}
for(int i = 7; line[i] != '\n' || line[i] != '\0'; ++i)
array[(i - 7) / size][(i - 7) % size] = line[i] - '0';
}
else
{
fclose(file);
for(int i = 0; i < size; ++i)
delete [] array[i];
delete [] array;
return -2; //incorrect format
}
return 0;
}
Don't forget delete array before program ends;
Loops.
FILE *fp = fopen("waaa.txt", "r");
if(fp == null) { /* bleh */ return; }
int j = 0;
while(char ch = fgetc(fp)) {
for(int i = 0; i < 4; ++i) {
array[j][i] = ch;
}
++j;
}
I am not sure with the fgetc() syntax.. Just check on it. It reads one character at a time.