File input/output help

eric_tran

GDay everyone, I need to save received characters into a file and display them to the screen later on in C programming. How to write a character pointed into a file in function A, and display it in a function B? Please help. Thanks in advance

eric

Eytukan

You can do that by many ways. You can use std::fstream , or the MFC's CFile or a direct "fopen" in C. Try searching these keys.

--[:jig:]-- [My Current Status] Link2006 wrote:Let's take it outside of CP Jeremy : Please don't.I would love to see this.I'm making the popcorn already.

singersinger

u can use fopen method to open a file like this FILE* pFile = fopen("file.txt", "a"); where "file.txt" is the file name and "a" is the mode (Opens for writing at the end of the file (appending)) u can learn more if u look for this function in the MSDN help use fprintf to write to the file fprintf(pFile, "%s\n",szString); where szString is any Character string !! note: dont forget to close the file fclose(pFile);

eric_tran

Thanks very much. Here is the code I've just done, but I can't display the right format Please give me a fix.

#include

void display(){
FILE *file1;
int numbers[30];
/* make sure it is large enough to hold all the data! */
int i,j;
//////////////////////
file1 = fopen("try.txt", "r");

if(file1==NULL) {
printf("Error: can't open file.\n");
}
else {
printf("File opened successfully.\n");

i = 0 ;    

while(!feof(file1)) { 
  /\* loop through and store into the array \*/
  fscanf(file1, "%s", numbers\[i\]);
  i++;
}

printf("Number of character read: %d\\n\\n", i);
printf("The message are:\\n");

for(j=0 ; j

eric

eusto

eric_tran wrote:

while(!feof(file1)) {
/* loop through and store into the array */
fscanf(file1, "%s", numbers[i]);
i++;
}

%s reads strings, you need numbers (cause you've declared numbers to be a pointer to int), try fscanf(file1, "%d", &numbers[1]);

eric_tran wrote:

for(j=0 ; j printf("%s\n", &numbers[j]); }

for(j = 0;j<i;j++)
printf("%d ", numbers[j]);

eric_tran

That's right. I forgot to change it. I'd actually want to display string only. Thanks

eric

eusto

easy way (not best)

#include int ReadAndStore(char lines[1024][1024])
{
int numberOfLinesRead = 0;
int i;//index

//try to open the file
FILE\* theFile = fopen("somefile", "r");
if(theFile==NULL)//if it fails
	return -1; //exit this function with -1

//read the file into lines
printf("Opened file for reading\\n");
numberOfLinesRead = 0;
while(fgets(lines\[numberOfLinesRead\],1023,theFile)&&numberOfLinesRead<1024)
{
	//you can also print your data here
	printf("%s", lines\[numberOfLinesRead\]);
	//increment line index;
	numberOfLinesRead++;
}
fclose(theFile);

//print data to screen
return numberOfLinesRead;//job well done

}

int main(int argc, char *argv[])
{
printf("scream if this is to big\n");
char fileContents[1024][1024];//should be enough
printf("i didn't scream\n");
int i;
int result = ReadAndStore(fileContents);
//if read returned 1..we exit
if(result==-1)
{
printf("Error reading file");
return 1;
}

FILE \*out = fopen("outfile","w");
if(out==NULL)
{
	printf("Error opening file");
	return 1;
}

//print lines to out
for(i = 0;i<result;i++)
	fputs(fileContents\[i\],out);

printf("i've read %d lines\\n",result);
//close file
fclose(out);
return 0;

}