Thread: Help creating multiple text files

Hello all,

I was trying to practice moving my programs into functions, so they are not only in the main() and also with creating files.

I can create a single file with no problem. However, I could not get my program to succeed with creating multiple files.

I want the program to be able to create say 4 text files each with a unique name and be concatenated with .txt at the end:

text1.txt
..
text4.txt

Could someone point out where I am going wrong please?

Here is the code I have done:

Code:

#include<stdio.h>

int file_generator(int number);


main()
{

int nrfiles = 4;


file_generator(nrfiles);

}


int file_generator(int number)
{

FILE  *nf;
int i=1;
char newfile[10];
for(i;i<=number;i++)
{

newfile[i] = "test";

nf = fopen(newfile[i], "w");

if (nf == NULL) {
  fprintf(stderr, "Can't open created file %s!\n",
          newfile);
  exit(1);
}
fclose(nf);
}
}

i am upset now.

I ammended the above program

so that"

Code:

nf = fopen(newfile[i], "w");

is just:

Code:

 nf = fopen(newfile, "w");

I compiled and ran the program and it produced this output files:

Code:

?0?????[?  ?0000??[?  000q?????  array    atm.c   file     matrix    test.txt
?00????[?  0000?????  00?q?????  array.c  conv    file.c   matrix.c
?000???[?  00000????  0??q?????

i ran rm ?*

and all my files were deleted
:-(

thanks matsp, I am trying that now. I mean to print out the names first.

I managed to get the function to print out a diffierent name by using an array.

I just cannot get the function to use this name now to create the file:

Code:

int file_generator(int number)
{         
char ch = 'a';
FILE  *nf;
int i=0; 
char newfile[number];

for(i;i<=number;i++)
  {   
   newfile[i] = ch;
   printf("%c\n", newfile[i]);
    
    
   nf = fopen(newfile[i], "w");
   if (nf == NULL) {
   fprintf(stderr, "Can't open created file %s!\n",
          newfile);
   exit(1);
   }
    
   if (nf == NULL) {
   fclose(nf);
   }
   ch = ch++;
  }

I kind of solved this with :

Code:

int file_generator(int number)
{         
char ch = 'a';
FILE  *nf;
int i=0; 
char newfile[number];

for(i;i<=number;i++)
  {   
   newfile[i] = ch ;
   printf("%c\n", newfile[i]);
    
   nf = fopen(newfile, "w");
   if (nf == NULL) {
   fprintf(stderr, "Can't open created file %s!\n",
          newfile[i]);
   exit(1); 
   }
    
   if (nf == NULL) {
   fclose(nf);
   } 

   ch = ch++;
  }
}

but it creates files like this:

Code:

:~/Programming$ ls
a  ab  abc  abcd  abcde  file  file.c

i am tired so I will go to bed

Hello there. I tried to do as you said matsp but I didn't manage. I am not sure how to do what you say:

Code:

you need to set the FIRST character of your array to whatever you want to call the file, and the second entry to 0. That way, you have a string of 1 character. You are currently setting position "i" in the array to the letter - that is not right.

I tried to do it a different way using pointers, but I get the same result:

Code:

int file_generator(int number)
{

char newfile[6] = {"TomB"};

char ch = 'a';
char *nfP;
nfP = &newfile;

FILE  *nf;
int i=0;

for(i;i<=number;i++)
  {
   printf("%c\n", *nfP);

   nf = fopen(nfP, "w");
   nfP++;
    if (nf == NULL) {
     fprintf(stderr, "Can't open created file %s!\n",
          nfP);
   exit(1);
   }

   if (nf == NULL) {
   fclose(nf);
   }
  }
}

which yields:

Code:

B  file  file.c  mB  omB  TomB

I feel like I am digging my own TomB here!

For the above program that I did to just take the array contents "TomB" and create from it files:

T
o
m
B

instead of the result stated above. I couldn't solve it :-(
I think it is slightly too much for me at this limited stage in my C experience.

Let me mess wit it - wit a hammer, if necessary!