b_frame

integer b_frame(data d, integer c);

is the position of the last occurrence of the c character in the d byte array if any, -1 otherwise

b_place

integer b_place(data d, integer c);

is the position of the first occurrence of the c character in the d byte array if any, -1 otherwise

b_probe

integer b_probe(data d, integer p, integer c);

is the position of the first occurrence of the c character not preceding the p position in the d byte array if any, -1 otherwise (negative position indications are interpreted with respect to the end of string)

See Negative Indices.

b_trace

integer b_trace(data d, integer p, integer c);

is the position of the last occurrence of the c character preceding the p position in the d byte array if any, -1 otherwise (negative position indications are interpreted with respect to the end of string)

See Negative Indices.