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Fjoin (3FML)

Name

Fjoin, Fjoin32-join source into destination buffer

Synopsis

#include stdio.h>  
#include "fml.h"  
int  
Fjoin(FBFR *dest, FBFR *src)  
#include "fml32.h"  
int  
Fjoin32(FBFR32 *dest, FBFR32 *src)

Description

Fjoin() is used to join two fielded buffers based on matching fieldid/occurrence. dest and src are pointers to the destination and source fielded buffers respectively. For fields that match on fieldid/occurrence, the field value is updated in the destination buffer with the value in the source buffer. Fields in the destination buffer that have no corresponding fieldid/occurrence in the source buffer are deleted.

This function may fail due to lack of space if the new values are larger than the old; in this case, the destination buffer will have been modified. However, if this happens, the destination buffer may be re-allocated using Frealloc(3) and the Fjoin() function repeated. Even if the destination buffer has been partially updated, repeating the function will give the correct results.

Fjoin32 is used with 32-bit FML.

Return Values

This function returns -1 on error and sets Ferror to indicate the error condition.

Errors

Under the following conditions, Fjoin() fails and sets Ferror to:

[FALIGNERR]

"fielded buffer not aligned"
Either the source buffer or the destination buffer does not begin on the proper boundary.

[FNOTFLD]

"buffer not fielded"
Either the source buffer or the destination buffer is not a fielded buffer or has not been initialized by Finit().

[FNOSPACE]

"no space in fielded buffer"
A field value is to be added or changed in a field buffer but there is not enough space remaining in the buffer.

Example

In the following example:

FBFR *src, *dest;  ...  if(Fjoin(dest,src)  0)  F_error("pgm_name");

if dest has fields A, B, and two occurrences of C, and src has fields A, C, and D, the resultant dest will have source field value A and source field value C.

See Also

Fintro(3), Fconcat(3), Fojoin(3), Fproj(3), Fprojcpy(3), Frealloc(3)

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