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endurox:v7.5.x:api:ubf:bextreadcb.3
Name
Bextreadcb — Restore the buffer from printed text received from callback function
Synopsis
#include <ubf.h>
int Bextreadcb (UBFH * p_ub, long (*p_readf)(char *buffer, long bufsz, void *dataptr1), void *dataptr1);
Link with -lubf -lnstd -lm -lpthread
DESCRIPTION
Restore the buffer from text populated by Bprint(3), Bprintf(3) or Bprintfcb(3).
The read format is "[COMMAND]<FIELD><TAB><VALUE><NEW_LINE>". Input also support fields by id, then format for <FIELD> is "((BFLDID32)<FIELD_ID>)".
Sample buffer:
T_SHORT_FLD 1765 T_LONG_FLD 3333111 T_LONG_FLD 2 T_CHAR_FLD A T_FLOAT_FLD 1.33000 T_DOUBLE_FLD 1111.220000 T_DOUBLE_FLD 333.000000 T_DOUBLE_FLD 444.000000 T_STRING_FLD HELLO WORLD T_CARRAY_FLD \00\01\02\03HELLO BINARY\04\05\00\\ ((BFLDID32)167772261) HELLOSVC
p_ub is buffer to write the data to, p_readf is function from which to read the line by line data. Each call to callback shall return zero terminated line with exactly one field, value and newline in the end. The bufsz denotes the buffer size of buffer, where data shall be put. In case if success, the p_readf must return number bytes written to buffer. At the end of the buffer, the p_readf must return 0. In case of error, callback function shall return -1. The dataptr1 passed to Bextreadcb() is forwarded to callback function and is meant to be used by user specific purposes. Field is optional and may be set to NULL, if not used by callback.
Input format supports also macro commands. This is optional COMMAND block, that can have following values:
+ set the field value at occurrence 0.
- delete field from buffer.
= copy the field value from field name which is stored at <VALUE>.
# comment, line ignored
For example:
# Set the field value T_SHORT_FLD 123 # Copy the value from T_SHORT_FLD to T_LONG_FLD =T_LONG_FLD T_SHORT_FLD # Change the occurrence 0 to 444 +T_SHORT_FLD 444
The final buffer will be:
T_SHORT_FLD 444 T_LONG_FLD 123
This format is used by ud(8) command line utility which allows to send arbitrary buffer to specified service.
RETURN VALUE
On success, Bextreadcb() return zero; on error, -1 is returned, with Berror set to indicate the error.
ERRORS
Note that Bstrerror() returns generic error message plus custom message with debug info from last function call.
BALIGNERR Corrupted buffer or pointing to not aligned memory area.
BNOTFLD Buffer not fielded, not correctly allocated or corrupted.
BEINVAL p_readf is NULL.
BSYNTAX Missing tab between field id or missing newline.
BBADNAME Field not found in field table.