Fgetc (): Read and save string of unknown length

Question

What I need to do for an appointment:

• open file (using fopen () function)
• read student name (using fgetc ())
• save this name in some part of the structure

The problem is that I need to read an arbitrary long line in the name, and I do not know how to save this line without losing memory (or writing to unallocated memory).

EDIT

My first idea was to allocate a 1-byte (char) block of memory, and then call realloc () if more bytes are needed, but that doesn't seem very efficient. Or maybe I could double the array if it is full, and then at the end copy the characters to a new memory block of the exact size.

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Answer 2

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Answer 3

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char name_buffer [ 80 ];

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int chars_read = 0; /* most compilers will init to 0 for you, but always good to be explicit */

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while ( ( chars_read < 80 ) && ( !feof( stdin ) ) ) {
  name_buffer [ chars_read ] = fgetc ( stdin );
  chars_read++;
}
if ( chars_read < 80 )
  name_buffer [ chars_read ] = '\0'; /* terminating null character */

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