ch64.htm

linux-unix130.linux.and.unix.ebooks130 linux and unix ebookslinuxLearning Linux - Collection of 12 E

	<LI><TT>-1</TT> to generate only 1D-encoded fax when sending.

</UL>





<DL>

	<DT></DT>

</DL>





<DL>

	<DD>

<HR>

<A NAME="Heading15<FONT COLOR="#000077"><B>CAUTION:</B> </FONT>There is no

	way to abort an incoming fax. Just sit back and wait until it's over.

<HR>



</DL>



<P>The <TT>faxd.recv</TT> daemon is the program that implements the server side of

the fax job submission protocol. It also implements extensions to this protocol to

support job removal and the return of status information. <TT>faxd.recv</TT> is normally

invoked by <TT>inetd</TT> with a line in the following form:<FONT COLOR="#0066FF"></FONT>

<PRE><FONT COLOR="#0066FF">fax stream tcp nowait fax /usr/libexec/faxd.recv  faxd.recv

</FONT></PRE>

<P>The <TT>faxd.recv</TT> daemon accepts requests for transmitting faxes and creates

the appropriate queue and document files in the HylaFAX spooling area. If a job is

received properly, a request to process the job is then sent to a fax server by writing

to a FIFO special file named <TT>FIFO</TT> in the spooling directory. The <TT>faxd.recv</TT>

daemon then returns a message to the sender indicating the Job ID (an integer number

associated with the job). This Job ID can be used later to remove the job from the

queue and to query the job's status.</P>

<P>Diagnostics generated by <TT>faxd.recv</TT> are logged with the <TT>syslog</TT>

facility. The user is always informed of any problem that affects the status of the

queued job. Check the man pages for a list of these error messages.

<H3 ALIGN="CENTER"><A NAME="Heading16<FONT COLOR="#000077">Sending a Fax</FONT></H3>

<P>To send a fax, you will use the <TT>sendfax</TT> program. The syntax for this

command from the man page is<FONT COLOR="#0066FF"></FONT>

<PRE><FONT COLOR="#0066FF">sendfax [ -a transmit-time ]

               [ -c comments ]

               [ -r regarding ]

               [ -x to-company ]

               [ -y to-location ]

               [ -d destination ]

               [ -f from ]

               [ -h host[:modem] ]

               [ -i identifier ]

               [ -k kill-time ]

               [ -lm ]

               [ -n ]

               [ -p ]

               [ -s pagesize-name     ]

               [ -t tries ]

               [ -v ]

               [ -DR ]

               [ files...  ]

</FONT></PRE>

<P><TT>sendfax</TT> queues up fax requests to a <TT>faxd</TT> server. These requests

normally are processed immediately, although they may also be queued for later transmission

using a syntax identical to the <TT>at</TT> command. For each job that is queued,

<TT>sendfax</TT> prints a job identifier on the standard output. This number can

be supplied to the <TT>faxrm</TT> command to remove the job or to the <TT>faxalter(1)</TT>

command to alter some of its parameters.</P>

<P>Fax documents are made from the concatenation of files specified on the command

line. If no files are supplied, <TT>sendfax</TT> reads data from the standard input

unless polling is requested. <TT>sendfax</TT> passes PostScript and TIFF documents

directly to the fax server for transmission and attempts to convert other file formats

to either PostScript or TIFF. In normal operation, <TT>sendfax</TT> automatically

converts ASCII-text or <TT>troff</TT> output before transmission.</P>

<P>By default, <TT>sendfax</TT> will generate a cover page for each fax that is transmitted.

This cover page is created by the faxcover program using information determined by

<TT>sendfax</TT> and by information supplied on the command line. The <TT>-x</TT>

option is used to specify the receiver's company; the <TT>-y</TT> option to specify

the receiver's geographical location; the <TT>-c</TT> option to specify a comments

field; and the <TT>-r</TT> option to specify a Re: subject. If a destination is specified

as <TT>user@fax-number</TT>, the user string is passed to <TT>faxcover</TT> as the

identity of the recipient.



<DL>

	<DT></DT>

</DL>





<DL>

	<DD>

<HR>

<A NAME="Heading17<FONT COLOR="#000077"><B>NOTE: </B></FONT>The preceding options

	must precede the <TT>-d</TT> option on the command line. Note also that multiword

	names must be enclosed in quote marks (<TT>&quot;</TT>).

<HR>



</DL>





<DL>

	<DD>

</DL>





<DL>

	<DD>

<HR>

<A NAME="Heading18<FONT COLOR="#000077"><B>TIP:</B> </FONT>If you don't want

	a cover page, specify the <TT>-n</TT> option.

<HR>



</DL>



<P>Here are a few other things about sending faxes:



<UL>

	<LI>You can use <TT>*70</TT>, on the <TT>-d</TT> parameter of <TT>sendfax</TT> when

	you want to disable call waiting.

	<P>

	<LI>By default, a fax is sent at low resolution (98 lines per inch). Medium resolution

	(196 lines per inch), often called <TT>fine mode</TT>, is requested with the <TT>-m</TT>

	option. Low resolution is requested with the <TT>-l</TT> option.

	<P>

	<LI>Faxes are on 8.5 x 11 pages unless otherwise configured. Other sizes include

	A3, ISO A4, ISO A5, ISO A6, ISO B4, North American Letter, American Legal, American

	Ledger, American Executive, Japanese Letter, and Japanese Legal.

	<P>

	<LI>By default, <TT>sendfax</TT> uses the <TT>FAXSERVER</TT> environment variable

	to identify the fax server to which the job should be directed. This can be overridden

	with a <TT>-h</TT> option. The server specified with the <TT>-h</TT> option, and

	by the environment variable, is a host name or address and, optionally, a modem identifier.

	The syntax for the latter is either <TT>host:modem</TT> or <TT>modem@host</TT>. For

	example, <TT>[e-mail]</TT>. If no modem is specified, the job will be submitted

	to any available modem.

</UL>



<P>If the first attempt to send a fax is unsuccessful, HylaFAX periodically tries

to resend the fax. By default, HylaFAX tries to transmit the fax for one day from

the time of the initial transmission. The <TT>-k</TT> option is used to specify an

alternate time for killing the job. This time is specified using notation compatible

with <TT>at</TT> and as a time relative to the time of the initial transmission attempt.</P>

<P>If an error is encountered while HylaFAX is processing a job, the fax server sends

an electronic mail message to the account submitting the job. If the <TT>-D</TT>

option is specified, HylaFAX also notifies the account by mail when the job is completed.

In addition, if the <TT>-R</TT> option is specified, notification also is returned

any time the job must be queued for retransmission.</P>

<P>Notification messages identify a job by its job identifier.</P>

<P>An arbitrary identification string can be specified instead with the <TT>-i</TT>

option.</P>

<P>If the <TT>-v</TT> option is specified, <TT>sendfax</TT> prints information on

the standard output about what <TT>sendfax</TT> does. If you specify <TT>--v -v</TT>,

even <TT>faxd.recv</TT> displays its status messages as it works.</P>

<P>See the man pages for more information on the options available with this <TT>sendfax</TT>

command.</P>

<P>Only two types of files are accepted by the fax server for transmission: PostScript

files or TIFF Class F (bi-level Group 3-encoded) files. All other types of files

must be converted to one of these two formats. The <TT>sendfax</TT> program applies

a set of rules against the contents of each input file to identify the file's type

and to figure out how to convert the file to a format that is suitable for transmission.

These rules are stored in the <TT>/usr/local/lib/HylaFAX/typerules</TT> file, an

ASCII file similar to <TT>/etc/magic</TT>. See the man pages on type rules for a

detailed look at how these type rules work.

<H3 ALIGN="CENTER"><A NAME="Heading19<FONT COLOR="#000077">Receiving Faxes</FONT></H3>

<P>Server processes can be configured to answer incoming phone calls and automatically

receive faxes. Received documents are placed in the <TT>recvq</TT> subdirectory as

TIFF Class F files. The server can be configured to make these files publicly accessible,

or they can be made private, in which case an administrator must manage their delivery.</P>

<P>When a fax is received, the server process invokes the <TT>bin/faxrcvd</TT> command.

The default command is a shell script that sends a mail message to a well-known user,

the <TT>FaxMaster</TT>, but you might also, for example, automatically spool the

document for printing.</P>

<P>Actually the man pages for HylaFAX are well written (for man pages). In the man

pages for <TT>faxd</TT>, you get a lot of detailed information about how received

faxes are handled.

<H3 ALIGN="CENTER"><A NAME="Heading20<FONT COLOR="#000077">Special Features</FONT></H3>

<P>HylaFAX comes with several features from creating cover pages and receiving incoming

data calls to handling polling requests. In each of these cases you can get more

information for the man pages for each command discussed in the remainder of this

chapter.

<H4 ALIGN="CENTER"><A NAME="Heading21<FONT COLOR="#000077">Cover Pages</FONT></H4>

<P>You generate PostScript cover sheets for your outgoing faxes with the <TT>faxcover</TT>

command. The syntax for this command from the man page is<FONT COLOR="#0066FF"></FONT>

<PRE><FONT COLOR="#0066FF">$ faxcover [ -t to-name ]

        [ -l to-location ]

        [ -x to-company ]

        [ -v to-voice-number ]

        [ -c comments ]

        [ -r regarding ]

        [ -p page-count ]

        [ -s pagesize-name ]

        [ -C  template-file ]

        -f from-name -n fax-number

</FONT></PRE>

<P>To generate the cover page for each outgoing fax, <TT>faxcover</TT> is invoked

by the <TT>sendfax</TT> program. <TT>Faxcover</TT> generates a PostScript cover-page

document on the standard output. The cover page fills the entire area of the default

page and is created according to the information supplied on the command line and

a cover sheet template file. The default template file is named <TT>faxcover.ps</TT>.

You can override the default cover sheet with the <TT>-C</TT> option by specifying

a file in the <TT>FAXCOVER</TT> environment variable.</P>

<P>If the cover sheet's filename is not an absolute path, <TT>faxcover</TT> looks

first for this file in the sender's home directory. If no such file is present, <TT>faxcover</TT>

looks in the library directory where the HylaFAX client application data is installed.

If no template file is located, <TT>faxcover</TT> terminates without generating a

cover page.

<H4 ALIGN="CENTER"><A NAME="Heading22<FONT COLOR="#000077">Polling</FONT></H4>

<P>HylaFAX supports the polled retrieval of fax documents. Documents received because

of a poll request are stored in the <TT>recvq</TT> subdirectory and also delivered

directly to the requester using the <TT>bin/pollrcvd</TT> command. This script typically

encodes the binary fax data and returns it to the recipient via e-mail.

<H4 ALIGN="CENTER"><A NAME="Heading23<FONT COLOR="#000077">Receiving Data Calls</FONT></H4>

<P>Most fax modems also support non-fax communications. HylaFAX uses the locking

mechanism employed by <TT>uucp</TT> and <TT>cu</TT>. Therefore, HylaFAX transparently

relinquishes the serial port when an application uses the modem for an outgoing call.

In addition, HylaFAX attempts to deduce whether an incoming call is for fax or data

use. If an incoming call comes from a data modem and the <TT>-g</TT> argument is

specified in the configuration file (or on the command line when the fax server process

is started), HylaFAX invokes the <TT>getty</TT> program so that the caller may log

in to the system.

<H4 ALIGN="CENTER"><A NAME="Heading24<FONT COLOR="#000077">Checking Status</FONT></H4>

<P>HylaFAX maintains status information in several forms. General status information

for each server process can be displayed by the <TT>faxstat(1)</TT> program. The

server processes may also be configured to log various kinds of debugging and tracing

information. For more information about configuration, see the section titled &quot;Installation

Steps&quot; in this chapter. The <TT>faxstat</TT> utility provides information such

as the remote status of jobs queued for transmission, jobs received, and the general

status of server processes. (See Listing 64.3.)

<H3 ALIGN="CENTER"><A NAME="Heading25<FONT COLOR="#000077">Listing 64.3. Output

of the faxstat command.</FONT><FONT COLOR="#0066FF"></FONT></H3>

<PRE><FONT COLOR="#0066FF"># faxstat

Server on localhost:cua1 for C: Running and idle.



Job  Modem Destination     Time-To-Send     Sender         Status

2    any   5551212                          root           Queued and waiting

1    any   5551212                          kamran         Being processed

Server on localhost:cua1 for C: Sending job 1 to 5796555.

</FONT></PRE>

<P>Any problems encountered during fax transmission are reported to the user by e-mail.

A user may also request notification by mail when a job is requeued. The server process

uses the <TT>/bin/notify</TT> command to inform the user via e-mail.</P>

<P>The file <TT>etc/xferlog</TT> contains status information about all faxes sent

and received. This file is in a simple ASCII format that is easy to manipulate with

programs such as <TT>vi</TT> or <TT>emacs</TT>.</P>

<P>To get more accounting information, use the following commands.



<UL>

	<LI><TT>xferlog</TT>--A log file of all transmitted files

	<P>

	<LI><TT>xferstats</TT>--Accounting information about all faxes sent or received

</UL>



<H4 ALIGN="CENTER"><A NAME="Heading26<FONT COLOR="#000077">E-Mail Setup</FONT></H4>

<P>It is easy to set up a simple mail-to-fax gateway facility with HylaFAX. If your

system uses <TT>sendmail</TT> to deliver mail, follow the instructions in the <TT>faxmail/mailfax.sh-sendmail</TT>

document. If your system uses <TT>smail</TT> (Linux users), follow the instructions