Thread: strcmp error

Code:

while(fgets(line,Char,que)!=NULL && strcmp(line,"quit") !=0)//when the command is not eof
    {
      strcpy(curline,line);
      //      printf("curline= %s\n",curline);
      token1=strtok(line," \n\t");//get the command
      while(token1 != NULL)//when command is not quit
        {
          if(strcmp("count",token1) ==0)//when command is count
            {
              printf("calling count\n");
              fflush(stdout);
              count();//call count
              printf("called count\n");
              fflush(stdout);
            }

Code:

void count(void)//the founction print out the number of relations
{
  char * token1;
  //  char * attname;
  char * str;
  int size;
  int x =0;
  int right =0;
  printf("curline in count  = %s\n", curline);
  token1 = strtok(curline, " \r\t\n");//use strtok to get the first word
  while(token1 != NULL)
    {
      printf("token1 %s\n",token1);
      token1 = strtok (NULL, " \r\t\n");//continue to part the string
    }
  printf("end of token\n");
  size =tableSize;//set size
  printf("size = %d\n",size);
  while(size>0 && right == 0)//if size is>0 and right is 0
    {
      str = relation[x].name;
      printf("str= %s\n",str);
      printf("token1= %s\n",token1);
      printf("1");
      if((strcmp(str,token1))==0)
        {
          printf("in strcmp\n");
          fflush(stdout);
          printf("There are %d of tuples in this relation. \n", schLine);//print
          right =1;
        }

I made few changes so it looks more clearly

output:
unix2% p3 config_file.txt query_file.txt
calling count
curline in count = count Students

token1 count
token1 Students
end of token
size = 2
str= Students
Segmentation Fault (core dumped)

thanks guys I found the error haha finally beat it!!!
the error is token == NULL after strtok is over and you cant print or compare it lol what a stupid mistake

Raise your hand if you understand why global variables make things difficult for you:

Code:

void count(void)//the founction print out the number of relations
{
  char * token1;
  //  char * attname;
  char * str;
  int size;
  int x =0;
  int right =0;
  printf("curline in count  = %s\n", curline);
  token1 = strtok(curline, " \r\t\n");//use strtok to get the first word
  while(token1 != NULL)
    {
      printf("token1 %s\n",token1);
      token1 = strtok (NULL, " \r\t\n");//continue to part the string
    }
  printf("end of token\n");
  size =tableSize;//set size
  printf("size = %d\n",size);
  while(size>0 && right == 0)//if size is>0 and right is 0
    {
      str = relation[x].name;

This is what now? And we know it's good because ... ?


Quzah.

Originally Posted by p595285902

str can be printed and it works fine I think you told me to use relation[x].nemae yesterday thx man

That has nothing to do with what I said. I said it's global, and we who are just looking at that function you provided us, have no idea what it is, or what value you may or may not have entered into it. I know what the syntax means. That doesn't mean I know what value it happens to have in it at runtime.

Why aren't you actually checking to see if tokens is null or not, instead of just trying to print it? Most sane implementations of printf just print (null) when they encounter one, but as far as I know it's not a requirement, so crashing is perfectly acceptable.


Quzah.