CSCI 235 — Checking return values

Various references

• Always check return value
• Error handling in C is primitive
• catch and throw
  • The original — LISP
  • try, throw and catch in C++
• C/Unix return value examples
  • fopen()
  • open()
  • fscanf()
  • fprintf()
• C/Unix error handling aids
  • errno
  • perror()
  • strerror()
• CERT recommentations
• Secure Coding in C and C++

The code you should write

    FILE *filePtr = fopen(fileName, "w") ;
    if (filePtr == NULL) {
      printf("open of %s failed: %s\n", fileName, strerror(errno)) ;
      return 1 ;
    }