c - Can't find the bug in the program to print the longest input line -

#include <stdio.h> #include <stdlib.h>  #define maxline 1000  int mygetline( char line[], int maxline); /*will return length */ void copy (char to[], char from[]);  int main(){      int len; // length of line     int max;  // maximum length seen far     char line[maxline];     char longest[maxline];      max = 0;     while((len = mygetline(line, maxline)) >0){         if (len>max){             max = len;             copy(longest, line);         }          if (max>0){              printf("%s", longest);         }     }     return 0; }  /*getline: reads line s, , returns length of line */ int mygetline(char s[], int limit){      int c, i;     for(i=0; i<limit-1 && (c=getchar())!= eof && c!= '\n'; ++i){         s[i] = c;     }      if (c=='\n'){         s[i] = c;         ++i;     }      s[i] = '\0';     return i; }  /*copy: copy 'from' 'to'; assume big enough */ void copy (char to[], char from[]){      int i=0;     while((to[i] = from[i] != '\0')){         ++i;     } } 

above stated code printing longest input line. code compiling without errors , yet when running program not printing anything. can't find going wrong in here.

this bit simpler , job using available string functions, instead of examining char char. if need to, can open file input , replace stdin.

#include <stdio.h> #include <string.h>  #define maxline 1000  int main(){     int len;    // length of line     int max;    // maximum length seen far     char line[maxline];     char longest[maxline];     char *sptr;     max = 0;     while((sptr = fgets(line, maxline, stdin)) != null) {         if ((sptr = strtok(sptr, "\r\n")) != null) {             len = strlen(sptr);             if (len > max) {                 max = len;                 strcpy(longest, sptr);             }         }     }     if (max)         printf("%d: %s\n", max, longest);     else          printf("no strings read\n");     return 0; }