i cant understand the error

Thu, 27 Mar 2008 07:44:59 -0700

i cant understand the error

Posted by on 27 Mar 2008 at 7:44 AM

this is the code

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
FILE *fpin, *fpout;
int ch,position;
unsigned line=1;
char filename[100];

printf("Please enter the file name\n");
scanf("%s",&filename);

if((fpin=fopen(filename,"r")) == NULL)
{
printf("Couldnt open file %s for input\n",filename);
exit(1);
}

if((fpout=fopen("res.txt","w")) == NULL)
{
printf("Couldnt open \"res.txt\" for output\n");
exit(1);
}

fprintf(fpout,"%d ",line);
while ((ch=getc(fpin)) != EOF)
if( ch == '\n')
{
putc(ch,fpout);
fprintf(fpout,"%d ",++line);
}
else
putc(ch,fpout);

fclose(fpin);
fclose(fpout);

return 0;
}

$ more input.txt
this is the first line
this is the second line
this is the third line

$ more res.txt
1 this is the first line
2 this is the second line
3 this is the third line
4

It seems that something happens and it cant read the EOF char.
OR even it reads it does something wrong.
I cant understand why.

I ve double-checked the input file if it has another new line char but it doesnt have one. I ve checked it with vi as well and there is no other char after the last char.

Could you please help me on this strange issue ?

Re: i cant understand the error

Thu, 27 Mar 2008 16:57:59 -0700

Re: i cant understand the error

Posted by on 27 Mar 2008 at 4:57 PM

Hi,

Are you completely sure the last 0x0A char isn't there ?

Editors like vi, vim, gedit, usually appends a new line \n even when you don't see it (I meant .. you can't see a new line, but you can't get into the next one also, but ... it's there!). Try to use :%!xxd inside vim on your input.txt (to filter with xxd and get the hexadecimal view, you can't edit from there, it's only a view). (A note, Microsoft Notepad doesn't add anything.)

Or use biew (F2 - Hex) or midnight commander mc (F3View - F4Hex) to observe that effectively the 0x0A char is there.

Even easier ... try :

cat input.txt
if you get this :
this is the last line
username@SERVER:~$
you have the \n but
if you get this :
this is the last lineusername@SERVER:~$
the \n isn't there.

Regards,

Good luck!
Hackman

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