Programming

Hi, i have some problems with the following code:

Code:

char *tab_path[num_classifiers];
char *sep=" \t\n";
char line[MAXLINE];
char *p;
FILE * file;
int i = 0;

if(fgets(line,MAXLINE,file)!=NULL){
        if((p=strtok(line,sep))!=NULL)tab_path[i]=p;
        while((p=strtok(NULL,sep))!=NULL){
            i++;
            tab_path[i]=p;
        }
    }

if(fgets(line,MAXLINE,file)!=NULL){
......
}

when the second fgets is executed tab_path variable is overwritten by the content of line variable. why?
thanks in advance

tab_path points to several places in the line variable. When you read new data into the line variable, tab_path reflects those changes as well.

ok, how can i avoid it happens??

You have to use the fields in tab_path first, then come back and read the next line.
Othwerwise you will have to create storage for the parsed fields, and strcpy each tab_path element into that storage.

If you have a big file, it makes more sense to parse each line into field, work with them then read a new line. IF you have to have the whole file in memory all at one time consider memory mapping the file. See beej's guide:
Memory Mapped Files

ok, thanks