Update Keyword Routines

These update routines modify the value of the keyword if it already exists, otherwise the new keyword is appended to the header.

1

Update an 80-character record in the CHU.

  int fits_update_card / ffucrd
      (fitsfile *fptr, char *keyname, char *card, > int *status)

2

Update the value and comment fields of a keyword in the CHU.

  int fits_update_key_str / ffukys
      (fitsfile *fptr, char *keyname, char *value, char *comment,
       > int *status)

  int fits_update_key_[log, lng] / ffuky[lj]
      (fitsfile *fptr, char *keyname, DTYPE numval, char *comment,
       > int *status)

  int fits_update_key_[flt, dbl, fixflt, fixdbl] / ffuky[edfg]
      (fitsfile *fptr, char *keyname, DTYPE numval, int decimals,
       char *comment, > int *status)

3

Update the value of an existing keyword to be undefined, or null, or insert a new undefined-value keyword if it doesn't already exist. The value string of the keyword is left blank in this case.

  int fits_update_key_null / ffukyu
      (fitsfile *fptr, char *keyname, char *comment, > int *status)