C Programming

Standard C fopen/fwrite lack file locking. Multiple processes can corrupt data. Need OS-specific locking (flock/fcntl on Unix) or use 'a' mode with small writes.

Fixed-size chunk processing is standard for large files. mmap() helps but may not be portable. Loading entire file exhausts memory. External tools bypass C programming.

Text mode on Windows converts CRLF to LF and vice versa, corrupting binary. Binary mode preserves exact bytes. Null byte handling is secondary concern.

rewind(fp) resets pointer AND clears EOF/error flags. fseek(fp, 0, SEEK_SET) only repositions. rewind is essentially: fseek(...); clearerr(...);

Single fread() for all records = 1 I/O operation. Loop-based approaches = 1000 operations. Fewer I/O calls = better performance.

Not checking fopen() return value leads to NULL pointer dereference. Buffer overflow and permissions cause different errors. Disk space affects writing.

Binary mode works for all files because it's just byte-for-byte copy. Text mode conversions are unnecessary for copying.

After fwrite() of 50 bytes from position 100, pointer moves to 150. File pointer advances after read/write operations.

Dynamic allocation with getc() handles variable-length lines robustly. fgets() with fixed buffer may truncate. fscanf() with %s doesn't handle spaces. Option D wastes memory.

Pure C solution uses fgets() to read lines and strstr() or manual checking for comment patterns. Option B uses external tool. Option D is inefficient.