smfi_chgheader()(3N) smfi_chgheader()(3N)
NAMEsmfi_chgheader() - changes or deletes a sendmail message header
SYNOPSISPARAMETERS
ctx Specifies the opaque context structure.
headerf Specifies the header name, which is a non-NULL, null-termi‐
nated string.
hdridx Specifies the header index value (1-based). A hdridx value
of 1 modifies the first occurrence of a header named If
hdridx is greater than the number of times appears, a new
copy of is added.
DESCRIPTION
changes the value of a header for the current message. can be called
only from the routine.
Notes
· While can be used to add new headers, it is more efficient to use
· A filter that calls must set the flag in the structure passed to
· The filter order is important for Filter placed later in the
sequence will observer the changes already done by earlier filters.
· The name and the value of the header are not checked for standards
compliance. However, each line of the header must be under 2048
characters. If longer headers are needed, multi-line header must be
used. To make a multi-line header, insert a linefeed (ASCII 0x0a,
or \n in C) followed by at least one whitespace character, such as,
a space (ASCII 0x20) or tab (ASCII 0x09, or \t in C). The linefeed
must not be preceded by a carriage return (ASCII 0x0d); the MTA adds
this automatically. It is the responsibility of the filter writer
to ensure that standards are not violated.
RETURN VALUE
returns due to the following reasons:
· headerf contains a NULL value.
· Modifying headers in the current connection state is invalid.
· Memory allocation fails.
· Network error occurs.
· is not set when is called.
returns on success.
EXAMPLESAUTHOR
was developed by the Sendmail Inc.
SEE ALSOsmfi_addheader(3N), smfi_insheader(3N), smfi_addrcpt(3N), smfi_delr‐
cpt(3N), smfi_replacebody(3N).
on
smfi_chgheader()(3N)