This code snippet reads lines from a file and finds...

This code snippet reads lines from a file and finds lines containing a specific substring. Here's a breakdown of what the code does:

1. Variable Initialization:

   int trovato = 0;
   

   • The variable trovato is initialized to 0. It acts as a flag to indicate if any matching line containing the substring was found (1 if found, 0 otherwise).

2. Reading the File:

   while (fgets(riga, sizeof(riga), file)) {
   

   • The fgets function reads a line from the file file into the buffer riga (assumed to be a character array declared earlier). It stops reading when it reaches the end of the line or the buffer size. The loop continues until all lines are read or EOF (end-of-file) is reached.

3. Searching for the Substring:

   if (strstr(riga, chiave)) {
   

   • The strstr(riga, chiave) function checks if the string chiave (assumed to be declared elsewhere) is found within the current line riga. If chiave exists within riga, this condition evaluates to true.

4. Outputting the Matching Line:

   fputs(riga, stdout);
   

   • If the substring chiave is found in riga, the matching line is printed to the standard output (stdout) using fputs.

5. Updating the Flag:

   trovato = 1;
   

   • The variable trovato is set to 1 to indicate that at least one matching line was found.

Summary:

This code searches for lines in a file that contain a specific substring (chiave). For each matching line, it prints the line to the standard output and sets the flag trovato to 1. At the end of the loop, trovato will indicate if a match was found (1) or not (0).