gd_alter_affixes(3) modify the field affixes of a fragments in a dirfile


#include <getdata.h>
int gd_alter_affixes(DIRFILE *dirfile, int fragment_index, const char *prefix, const char *suffix);


The gd_alter_affixes() function sets the field prefix and suffix of fields defined in the format specification fragment given by fragment_index to prefix and suffix in the dirfile(5) database specified by dirfile.

The field prefix and suffix are appended to all field codes found in the specified fragment. If the parent fragment to the modified fragment contains field affixes themselves, they should be included in the affixes passed to gd_alter_affixes(). See EXAMPLES below for further details. If prefix or suffix is NULL, the corresponding affix will be unchanged. To remove an affix, set it to the parent fragment's corresponding affix, which may be the empty string ("").

It is not possible to set affixes on the root format file (i.e. fragment_index may not be zero).

The dirfile argument must point to a valid DIRFILE object previously created by a call to gd_open(3).


Upon successful completion, gd_alter_affixes() returns zero. On error, it returns -1 and sets the dirfile error to a non-zero error value. Possible error values are:
The specified dirfile was opened read-only.
The library was unable to allocate memory.
The supplied prefix or suffix contained invalid characters.
The supplied dirfile was invalid.
The supplied index was out of range.
The supplied affixes would result in one or more field codes duplicating an existing field code.
The metadata of the given fragment's parent fragment was protected from change.

The dirfile error may be retrieved by calling gd_error(3). A descriptive error string for the last error encountered can be obtained from a call to gd_error_string(3).


Dealing with affixes of parent fragments is relatively straightforward. Say, for instance, fragment #1 has a prefix "A" and a suffix "B" and fragment #2 is included from fragment #1. In this case any prefix for fragment #2 must end with "A" and any suffix for fragment #2 must begin with "B".