Introduction / Context:
On Windows, text files commonly use CRLF line endings, represented as carriage return followed by newline (\r\n). Understanding how fgets handles these characters is key to correctly parsing input and trimming line endings for cross-platform applications.
Given Data / Assumptions:
- The file contains the exact byte sequence for the line: letters plus \r\n before end of line.
- fgets reads up to and including the first \n, or until the buffer limit or EOF.
- There is sufficient buffer space to hold the entire line and terminator.
Concept / Approach:
- fgets copies characters from the stream into the buffer until it either copies a \n, reaches size-1, or hits EOF.
- Whatever precedes \n (including a preceding \r) is also copied verbatim.
- After copying, fgets appends a null terminator \0.
Step-by-Step Solution:
Input stream bytes → 'I am a boy\r\n'.fgets copies bytes until and including \n, so both \r and \n end up in the buffer.fgets appends \0, yielding 'I am a boy\r\n\0' in memory.
Verification / Alternative check:
Printing with debugging or inspecting byte values shows 0x0D (\r), 0x0A (\n), followed by 0x00.
Why Other Options Are Wrong:
- "I am a boy\r\0": Would imply fgets stops at \r, which it does not; it stops after copying \n.
- "I am a boy\n\0": Ignores the presence of \r in the file.
- "I am a boy": Omits both line breaks and the terminator, which is incorrect for fgets.
Common Pitfalls:
- Assuming fgets strips line endings; it keeps the \n if present and any preceding \r.
- For cross-platform trimming, explicitly remove trailing \r and \n as needed.
Final Answer:
"I am a boy\r\n\0"
Discussion & Comments