I have the code below which compiles fine in xcode, but when I take it across to Microsoft Visual studio I get a bunch of errors.
void openfile(int mapArray[MAX_HEIGHT][MAX_WIDTH], int *interest, int *dimension1, int *dimension2)
{
int counter = 0;
char buffer;
int rowss, colss;
*interest = 0;
FILE *f;
f = fopen(FILENAME, "r");
if (f==NULL) {
printf("Map file could not be opened");
return 0;
}
// create char array the dimensions of the map
fscanf(f, "%d %d" , dimension1, dimension2 );
// printf("%d %d\n" , dimensions[0], dimensions[1]);
// Reads the spaces at the end of the line till the map starts
buffer=fgetc(f);
while (buffer!='*') {
buffer=fgetc(f);
}
// Read the txt file and print it out while storing it in a char array
while (buffer!=EOF) {
mapArray[rowss][colss]=buffer;
colss++;
// Count up the points of interest
if (((buffer>64)&&(buffer<90))||(buffer=='#') ) {
counter++;
}
// resets column counter to zero after newline
if (buffer=='\n') {
colss=0;
rowss++;
}
buffer=fgetc(f);
}
// Closes the file
fclose(f);
*interest=counter;
}
Which parts are creating all the errors?
I get this list of errors when attempting to compile
Thanks in advance.
I see a few immediate problems. First, you're not initialising rowss or colss before you use them, hence they could contain any value.
Second, fgetc() returns an int so that you can detect end of file. By using a char to hold the return value, you're breaking the contract with the standard library.
Thirdly, you return a 0 if the filename couldn't be opened, despite the fact that the function is specified to return void (ie, nothing).
No doubt those are three of the errors the compiler picked up on, there may be others, and you should probably post the error list with your question for a more exhaustive analysis.
Related
I'm developing some code in C that reads a file extension and stores it as a code in a byte together whether a text file or binary file is being processed. Later I wish to recover the file extension that is encoded in a byte.
As a test I created a loop in the main function where I can test out the function fileExtenCode(), which is in the second listing.
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#define EXLEN 9
#define EXNUM 8
typedef unsigned char BYTE;
bool fileExtenCode(char*, BYTE*, int*);
int main(void) {
char fileExten[EXLEN];
BYTE code;
int bin;
for (;;) {
printf("Type file extension: ");
scanf_s("%s", fileExten, EXLEN);
if (fileExten[0] == '.') break;
printf("%s\n", fileExten);
code = 0;
bin = 0;
bool extFound = fileExtenCode(fileExten, &code, &bin); // <== (1)
if (extFound) printf("Extension found: TRUE\n");
else printf("Extension found: FALSE\n");
printf("%s%d", "Code: ", code);
if (bin) printf(" binary file\n");
else printf(" text file\n");
printf("\n");
printf("Type code: ");
int icode;
scanf_s("%d", &icode);
code = icode;
bin = -1;
fileExtenCode(fileExten, &code, &bin); // <== (2)
printf("%s", fileExten); // <== (5)
printf("\n");
}
return 0;
}
The function that I'm trying to test is as follows:
bool fileExtenCode(char* ext, BYTE* code, int* binary) {
char *fileEx[EXNUM] = {
"jpg1", "txt0", "html0", "xml0", "exe1", "bmp1", "gif1", "png1"};
if (*binary < 0) { // <== (3)
ext = fileEx[*code]; // <== (4)
return true;
}
size_t extLen = strlen(ext);
for (BYTE i = 0; i < EXNUM; i++) {
if (strncmp(fileEx[i], ext, extLen) == 0) {
*binary = (fileEx[i][extLen] == '1') ? 1 : 0;
*code = i;
return true;
}
}
return false;
}
The idea is that you pass a string with the file extension to fileExtenCode() in statement (1) in main, and the function searched for that extension in an array, and if found returns true together with the code argument indicating the position in array of file extensions and the binary flag as 0 or 1 indicating if the file is text or binary. A '0' or '1' immediately follows file extension in the array. If the extension is not found, the function returns with false and the return values in the arguments have no meaning.
So far so good, and this part works correctly. However, in using the function in reverse to recover the file extension given the input value of code, it fails when called with statement (2) in main. In this case binary is set to -1, and then the function is called and the condition at (3) is now true and ext in (4) recovers the file extension. This is confirmed when inserting a temporary print statement immediately after (4), but this value is not returned in (5) back in main, and an old input value is instead printed.
Obviously there is a problem with pointers, but I cannot see an obvious way of fixing it. My question is how to correct this without messing up the rest of the code, which is working correctly? Note that char* ext and BYTE* code are used for both input and output, whilst int* binary is used as an input flag and returns no useful value when set to -1.
Once this problem is fixed, then it should be relatively easy to separate the binary flag from the extension when the binary flag is set to -1. Eventually I plan to have many more file extensions, but not until this is working correctly with a sample of 8.
Getting help in fixing this problem would be most appreciated.
OK, many thanks pmg, that works, except that I have to use:
strcpy_s(ext, EXLEN, fileEx[*code]);
as the Visual Studio 2022 compiler flags an error. This also solves a warning I was getting when I declared the array *fileEx[EXNUM] with the const keyword.
In my haste last night I omitted to include the statement:
if (*code >= EXNUM) return false;
immediately after (3) to trap the case when *code goes out of bounds of *fileEx[EXNUM].
I have to write a function that given two files, compares them both and writes on a third file each word they have in common, I tried with this one, actually making it write on terminal to see if it works, it actually iterates trough the second file but it only compares the first word of the first file, any suggestions?
void fileCopy(FILE *f1,FILE *f2){
char fileString1[100], fileString2[100];
while(!feof(f1)){
fscanf(f1,"%s",fileString1);
while(!feof(f2)){
fscanf(f2,"%s",fileString2);
if(!strcmp(fileString1,fileString2)) printf("%s ",fileString1);
}
}
}
while(!feof(f2)) loops until the end of the second file. You must iterate through both files simultaneously. Instead of these while(!feof... you should be checking the result of each fscanf.
A simple pseudo code example:
while(1)
{
int fscanf1_result = fscanf(f1, ...);
int fscanf2_result = fscanf(f2, ...);
if(fscanf1_result != 1 || fscanf2_result != 1)
{
break;
}
/* rest of the code here */
};
So I have to write a program that prompts the user to enter the name of a file, using a pointer to an array created in main, and then open it. On a separate function I have to take a user defined string to a file opened in main and return the number of lines in the file based on how many strings it reads in a loop and returns that value to the caller.
So for my first function this is what I have.
void getFileName(char* array1[MAX_WIDTH])
{
FILE* data;
char userIn[MAX_WIDTH];
printf("Enter filename: ");
fgets(userIn, MAX_WIDTH, stdin);
userIn[strlen(userIn) - 1] = 0;
data = fopen(userIn, "r");
fclose(data);
return;
}
For my second function I have this.
int getLineCount(FILE* data, int max)
{
int i = 0;
char *array1[MAX_WIDTH];
if(data != NULL)
{
while(fgets(*array1, MAX_WIDTH, data) != NULL)
{
i+=1;
}
}
printf("%d", i);
return i;
}
And in my main I have this.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define MAX_WIDTH 144
void getFileName(char* array1[MAX_WIDTH]);
int getLineCount(FILE* data, int max);
int main(void)
{
char *array1[MAX_WIDTH];
FILE* data = fopen(*array1, "r");
int max;
getFileName(array1);
getLineCount(data, max);
return 0;
}
My text file is this.
larry snedden 123 mocking bird lane
sponge bob 321 bikini bottom beach
mary fleece 978 pasture road
hairy whodunit 456 get out of here now lane
My issue is that everytime I run this I keep getting a 0 in return and I don't think that's what I'm supposed to be getting back. Also, in my second function I have no idea why I need int max in there but my teacher send I needed it, so if anyone can explain that, that'd be great. I really don't know what I'm doing wrong. I'll appreciate any help I can get.
There were a number of issues with the posted code. I've fixed the problems with the code and left some comments describing what I did. I do think that this code could benefit by some restructuring and renaming (e.g. array1 doesn't tell you what the purpose of the variable is). The getLineCount() function is broken for lines that exceed MAX_WIDTH and ought to be rewritten to count actual lines, not just calls to fgets.
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define MAX_WIDTH 144
/**
* Gets a handle to the FILE to be processed.
* - Renamed to indicate what the function does
* - removed unnecessary parameter, and added return of FILE*
* - removed the fclose() call
* - added rudimentary error handling.
**/
FILE *getFile()
{
char userIn[MAX_WIDTH+1];
printf("Enter filename: ");
fgets(userIn, MAX_WIDTH, stdin);
userIn[strlen(userIn) - 1] = 0; // chop off newline.
FILE *data = fopen(userIn, "r");
if (data == NULL) {
perror(userIn);
}
return data;
}
/**
* - removed the unnecessary 'max' parameter
* - removed null check of FILE *, since this is now checked elsewhere.
* - adjusted size of array1 for safety.
**/
int getLineCount(FILE* data)
{
int i = 0;
char array1[MAX_WIDTH+1];
while(fgets(array1, MAX_WIDTH, data) != NULL)
{
i+=1;
}
return i;
}
/**
* - removed unnecessary array1 variable
* - removed fopen of uninitialized char array.
* - added some rudimentary error handling.
*/
int main(void)
{
FILE *data = getFile();
if (data != NULL) {
int lc = getLineCount(data);
fclose(data);
printf("%d\n", lc);
return 0;
}
return 1;
}
There are several things I think you should repair at first:
getFileName should help you getting the file name (as the name says), so in that function you shouldn’t have both array1 and userIn (as a matter of fact array1 is not even used in the function, so it can be eliminated all togheter). The paramater and the file name should be ‘the same’.
data is a local FILE pointer, this means once you exit the function you lose it. My recommandation is to make it global, or pass it as an argument from the main class. Also do not close it 1 line after you open it.
I guess the getLineCount is fine, but usually is a good practice to return and printf in main what is returned.
That max that is passed to the second function maybe to help you with the max size of a line? it might be.
Summing up, your getFileName should return the file name, so that userIn is what should be given by that parameter. The File opening should be done IN THE MAIN FUNCTION and be closed after everything you do related to the file, so at the end. Also, open the file after you get the name of the file.
Hopefully it helps you! Keep us tuned with your progress.
I have scanned "ABCDEFGHIJK" with fscanf into a char array[26]. Then I got "ABCDEFGHIJK" using "for" into another array[11]. Now I need to get to an "ABCDEFGHIJK.mp4" array[15] in order to feed that filename into a rename function.
I don't know much about C programming besides printf, scanf, for and while.
sprintf(filename, "%c%c%c%c%c%c%c%c%c%c%c.mp4", codigo[0], codigo[1], codigo[2], codigo[3], codigo[4], codigo[5], codigo[6], codigo[7], codigo[8], codigo[9], codigo[10]);
This code above seems to work, but I wonder if there is a simpler way (especially for bigger arrays)?
Clarification: I have a txt file, formatted with these containing the filenames without extension and the human filename. I'm trying to make a program that will rename these files to the correct name, as they are from a backup that failed.
EDIT: Here is the full program. I renamed the variables to make more sense, so "codigo" is now "idcode".
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main(void)
{
int i, j, k;
char value1[26], value2[70], idcode[11], filename[16], fullname[64], filenamestring[16], fullnamestring[64];
// Opening file.
FILE *nomes;
nomes = fopen("/Users/EA/Desktop/Songs/backup.txt", "rt");
if(nomes == NULL)
{
printf("Erro ao abrir backup.txt");
exit(1);
}
// Skipping beggining of file until first value.
for(i=0; i<10; i++)
{
fscanf(nomes, "%*s");
}
// Reading first value, and repetition.
while(fscanf(nomes, "%s", value1) == 1)
{
j = k = 0;
// Extracting idcode from value1.
for(i=7; i<18; i++)
{
idcode[j] = value1[i];
j++;
}
// Filling the complete filename.
sprintf(filename, "%.*s.mp4", 11, idcode);
// Reading second value, the "human" filename.
fscanf(nomes, "\n%[^\n]", value2);
for(i=6; i<70; i++)
{
fullname[k] = value2[i];
k++;
}
// Transforming filenames into strings for rename function.
strncpy(filenamestring, filename, 16);
strncpy(fullnamestring, fullname, 64);
// Renaming the files.
rename(filename, fullname);
// Skipping useless data before the next cycle.
for(i=0; i<9; i++)
{
fscanf(nomes, "%*s");
}
}
// Closing file and ending program.
fclose(nomes);
return(0);
}
It looks like you got an array of char's.
You can simply do:
sprintf(filename, "%.*s.mp4", 11, codigo)
You can read more about the %.*s specifier in this question.
If you just want to append the format ".mp4" to the end of the string the easiest way to do that is just:
strcat(filename,".mp4");
after you printed the name without the ".mp4" into it.
If you really want to use sprintf then i think this should suffice:
sprintf(filename,"%s.mp4", codigo);
Also,if you want your string to be bigger and not fixed in size you can put "\0" at the end of it(this might not work if you try to use the strings in other programming languages but c) with strcat as above,or you can do this:
memset(&filename, 0, sizeof(filename));
I am making program in C which can search for a specific string in a large .txt file and count it and then print it out. But it seems that something have go wrong, cause the output of my program is different from that of the two text editor. According to the text editor, there are totally 3000 words,in this case I search for the word "make", in that .txt file. But the output of my program is just 2970.
I cannot find out the problem of my program. So I am curios about how could a text editor search for a specific string so accurately? How do people implement that? Can any people show me some code in C?
To make things clear: that is a large .txt file, 20M or so, containing lots of characters. So I think it's not so good to read it into memory all at once. I have implement my program by splitting my program in to pieces and then scan all of those for parsing. However, it fail some way.
Maybe I should put the code here. Wait a minute please.
The code is kinda long, 70 lines or so. I have put it on my github, if you have any interest, please help. https://github.com/walkerlala/searchText
note that the only related file is wordCount.c and testfile.txt which goes like:
#include<stdio.h>
#include<stdlib.h>
#include<stdbool.h>
char arr[51];
int flag=0;
int flag2=0;
int flag3=0;
int flag4=0;
int pieceCount(FILE*);
int main()
{
//the file in which I want to search the word is testfile.txt
//I have formatted the file so that it contain no newlins any more
FILE* fs=fopen("testfile.txt","r");
int n=pieceCount(fs);
printf("%d\n",n);
rewind(fs); //refresh the file...
static bool endOfPiece1=false,endOfPiece2=false,endOfPiece3=false;
bool begOfPiece1,begOfPiece2,begOfPiece3;
for(int start=0;start<n;++start){
fgets(arr,sizeof(arr),fs);
for(int i=0;i<=46;++i){
if((arr[i]=='M'||arr[i]=='m')&&(arr[i+1]=='A'||arr[i+1]=='a')&&(arr[i+2]=='K'||arr[i+2]=='k')&&(arr[i+3]=='E'||arr[i+3]=='e')){
flag+=1;
//continue;
}
}
//check the border
begOfPiece1=((arr[1]=='e'||arr[1]=='E'));
if(begOfPiece1==true&&endOfPiece1==true)
flag2+=1;
endOfPiece1=((arr[47]=='m'||arr[47]=='M')&&(arr[48]=='a'||arr[48]=='A')&&(arr[49]=='k'||arr[49]=='K'));
begOfPiece2=((arr[1]=='k'||arr[1]=='K')&&(arr[2]=='e'||arr[2]=='E'));
if(begOfPiece2==true&&endOfPiece2==true)
flag3+=1;
endOfPiece2=((arr[48]=='m'||arr[48]=='M')&&(arr[49]=='a'||arr[49]=='A'));
begOfPiece3=((arr[1]=='a'||arr[1]=='A')&&(arr[2]=='k'||arr[2]=='K')&&(arr[3]=='e'||arr[3]=='E'));
if(begOfPiece3==true&&endOfPiece3==true)
flag4+=1;
endOfPiece3=(arr[49]=='m'||arr[49]=='M');
}
printf("%d\n%d\n%d\n%d\n",flag,flag2,flag3,flag4);
getchar();
return 0;
}
//the function counts how many pieces have I split the file into
int pieceCount(FILE* file){
static int count=0;
char arr2[51]={'\0'};
while(fgets(arr2,sizeof(arr),file)){
count+=1;
continue;
}
return count;
}
You can do this quite simply just by having a rolling buffer. You don't need to break the file into sections.
#include <stdio.h>
#include <string.h>
int main(void) {
char buff [4]; // word buffer
int count = 0; // occurrences
FILE* fs=fopen("test.txt","r"); // open the file
if (fs != NULL) { // if the file opened
if (4 == fread(buff, 1, 4, fs)) { // fill the buffer
do { // if it worked
if (strnicmp(buff, "make", 4) == 0) // check for target word
count++; // tally
memmove(buff, buff+1, 3); // shift the buffer down
} while (1 == fread(buff+3, 1, 1, fs)); // fill the last position
} // end of file
fclose(fs); // close the file
}
printf("%d\n", count); // report the result
return 0;
}
For simplicity I stopped short of making the search word "softer" and allocating the correct buffer and various sizes, since that wasn't in the question. And I have to leave something for OP to do.