Strange chars while reading from file with fgetc

Question

When I printf the variable answer it contains several strange chars. What might be the reason?

int flag=0;
char answer[512];
char a[2];
a[1]='\0';

int c;
int status=1;
do {
      c = fgetc(pp);
      if( feof(pp) ) {
         break ;
        }
        if(c=='F' || status==0){
                a[0]=(char)c;
                strcat(answer,a);
                status=0;
        }
   } while(TRUE);

Perhaps the file contained strange chars – M.M Dec 14 '17 at 01:32 — M.M, Dec 14 '17 at 01:32

score 2 · Accepted Answer · answered Dec 14 '17 at 01:43

2

strcat expects the destination string to be valid - which means it must be null terminated. You are not explicitly null terminating the answer string. Add answer[0]=0 before your loop.

answered Dec 14 '17 at 01:43

MFisherKDX

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@chux. I think the OP got `a[1]=0` correct. But missed `answer[0]=0`. – MFisherKDX Dec 14 '17 at 02:28
Yes, comment deleted. – chux - Reinstate Monica Dec 14 '17 at 03:15
thanks @MFisherKDX your suggestion was the fix. So even an empty string must be terminated with a 0? – Tosh Dec 16 '17 at 00:19

Strange chars while reading from file with fgetc

1 Answers1