linux programming in C

• open() int open(const char *pathname, int flags)
  int open(const char *pathname, int flags, mode_t mode)
  see the man page
  
  • pathname: a string with the full or relative pathname of the file
  • O_RDONLY, O_WRONLY, O_RDWR, O_CREAT, O_EXCL, O_NOCTTY....
  • third option: the permission bits to be used for that file creation ONLY

  example

  #include 
  #include 
  #include 
  /* open.c */
  int open(const char * pathname, int flags).
  int open(const char *pathname, int flags, mode_t mode);
  STDOUT: 
  open.c.8:warning: extern declaration of 'open' doesn't match global one