Thread: Trouble with fgets() and strstr()

Hi everyone.
I'm working with string functions, but I have a trouble with strstr(). Here is the code that works:

Code:

char text[] = "one two three";
  char substring[] = "two";

  if(strstr(text, substring))
    puts("The string sought was found");
  else
    puts("The string sought was not found");

This is the code that doesn't work:

Code:

#define TEXT_LEN 100
#define SUBSTRING_LEN 40

  char text[TEXT_LEN];
  char substring[SUBSTRING_LEN];

  printf("Enter the text to be searched:\n");
  fgets(text, TEXT_LEN, stdin);

  printf("Enter the string sought:\n");
  fgets(substring, SUBSTRING_LEN, stdin);

  if(strstr(text, substring))
    puts("The string sought was found");
  else
    puts("The string sought was not found");

Why strstr() returns NULL even when substring is in text?

I'am working on a GNU/linux system.
Thanks.

Don't forget that fgets() retrieves the end of line character and places it in the string, you need to take this into account.

Jim

"fgets()" also stores the newline, if there is room. So entering your original input would yield the following strings:

"one two three\n"
"two\n"

So "two\n" is not a substring of the first. See here for an example of reading input from stdin with "fgets()" and removing the newline, if present: FAQ > Get a line of text from the user/keyboard (C) - Cprogramming.com

#define TEXT_LEN 100
#define SUBSTRING_LEN 40

char text[TEXT_LEN];
char substring[SUBSTRING_LEN];

printf("Enter the text to be searched:\n");
fgets(text, TEXT_LEN, stdin);

printf("Enter the string sought:\n");
fgets(substring, SUBSTRING_LEN, stdin);

if(substring[strlen(substring)-1] =='\n')
substring[strlen(substring)-1] = '\0';

if(strstr(text, substring))
puts("The string sought was found");
else
puts("The string sought was not found");



Neetu