9.3.6 Modify Keyword Routines

These routines modify the value of an existing keyword. An error is returned if the keyword does not exist. Wild card characters may be used when specifying the name of the keyword to be modified. See Appendix B for the definition of the parameters used in these routines.

1

Modify (overwrite) the nth 80-character header record in the CHU.

  int fits_modify_record / ffmrec
      (fitsfile *fptr, int keynum, char *card, > int *status)

2

Modify (overwrite) the 80-character header record for the named keyword in the CHU. This can be used to overwrite the name of the keyword as well as its value and comment fields.

  int fits_modify_card / ffmcrd
      (fitsfile *fptr, char *keyname, char *card, > int *status)

5

Modify the value and comment fields of an existing keyword in the CHU. The `longstr' version has the same functionality as the `str' version except that it also supports the local long string keyword convention for strings longer than 68 characters. Optionally, one may modify only the value field and leave the comment field unchanged by setting the input COMMENT parameter equal to the ampersand character (&) or by entering a null pointer for the comment parameter. The flt, dbl, cmp, and dblcmp versions of this routine have the added feature that if the 'decimals' parameter is negative, then the 'G' display format rather then the 'E' format will be used when constructing the keyword value, taking the absolute value of 'decimals' for the precision. This will suppress trailing zeros, and will use a fixed format rather than an exponential format, depending on the magnitude of the value.

  int fits_modify_key_[str, longstr] / ffm[kys, kls]
      (fitsfile *fptr, char *keyname, char *value, char *comment,
       > int *status);

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

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

  int fits_modify_key_[cmp, dblcmp, fixcmp, fixdblcmp] / ffmk[yc,ym,fc,fm]
      (fitsfile *fptr, char *keyname, DTYPE *numval, int decimals,
       char *comment, > int *status)

6

Modify the value of an existing keyword to be undefined, or null. The value string of the keyword is set to blank. Optionally, one may leave the comment field unchanged by setting the input COMMENT parameter equal to the ampersand character (&) or by entering a null pointer.

  int fits_modify_key_null / ffmkyu
      (fitsfile *fptr, char *keyname, char *comment, > int *status)