man: add man pages for dbfp_query_departure, dbfp_departure_close

7 files changed, 577 insertions, 4 deletions

diff --git a/Makefile b/Makefile
index ac2048b..d912aad 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ clean:
 	$(RM) dbfp_check
 	$(RM) dbfp.o dbfp_check.o
 
-doc: man/dbfp_close.3 man/dbfp_init.3 man/dbfp_location_close.3 man/dbfp_query_location.3
+doc: man/dbfp_close.3 man/dbfp_init.3 man/dbfp_departure_close.3 man/dbfp_location_close.3 man/dbfp_query_departure.3 man/dbfp_query_location.3
 
 memcheck: libdbfp.so dbfp_check
 	LD_LIBRARY_PATH=. CK_FORK=no valgrind --tool=memcheck ./dbfp_check
@@ -36,12 +36,18 @@ memcheck: libdbfp.so dbfp_check
 man/dbfp_close.3: man/dbfp_close.pod
 	pod2man -c "DB timetable API" -n "DBFP_CLOSE" -r $(VERSION) -s 3 $^ > $@
 
+man/dbfp_departure_close.3: man/dbfp_departure_close.pod
+	pod2man -c "DB timetable API" -n "DBFP_DEPARTURE_CLOSE" -r $(VERSION) -s 3 $^ > $@
+
 man/dbfp_init.3: man/dbfp_init.pod
 	pod2man -c "DB timetable API" -n "DBFP_INIT" -r $(VERSION) -s 3 $^ > $@
 
 man/dbfp_location_close.3: man/dbfp_location_close.pod
 	pod2man -c "DB timetable API" -n "DBFP_LOCATION_CLOSE" -r $(VERSION) -s 3 $^ > $@
 
+man/dbfp_query_departure.3: man/dbfp_query_departure.pod
+	pod2man -c "DB timetable API" -n "DBFP_QUERY_DEPARTURE" -r $(VERSION) -s 3 $^ > $@
+
 man/dbfp_query_location.3: man/dbfp_query_location.pod
 	pod2man -c "DB timetable API" -n "DBFP_QUERY_LOCATION" -r $(VERSION) -s 3 $^ > $@
 
diff --git a/man/dbfp_departure_close.3 b/man/dbfp_departure_close.3
new file mode 100644
index 0000000..4e2aef1
--- /dev/null
+++ b/man/dbfp_departure_close.3
@@ -0,0 +1,154 @@
+.\" Automatically generated by Pod::Man 4.07 (Pod::Simple 3.32)
+.\"
+.\" Standard preamble:
+.\" ========================================================================
+.de Sp \" Vertical space (when we can't use .PP)
+.if t .sp .5v
+.if n .sp
+..
+.de Vb \" Begin verbatim text
+.ft CW
+.nf
+.ne \\$1
+..
+.de Ve \" End verbatim text
+.ft R
+.fi
+..
+.\" Set up some character translations and predefined strings.  \*(-- will
+.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
+.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
+.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
+.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
+.\" nothing in troff, for use with C<>.
+.tr \(*W-
+.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
+.ie n \{\
+.    ds -- \(*W-
+.    ds PI pi
+.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
+.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
+.    ds L" ""
+.    ds R" ""
+.    ds C` ""
+.    ds C' ""
+'br\}
+.el\{\
+.    ds -- \|\(em\|
+.    ds PI \(*p
+.    ds L" ``
+.    ds R" ''
+.    ds C`
+.    ds C'
+'br\}
+.\"
+.\" Escape single quotes in literal strings from groff's Unicode transform.
+.ie \n(.g .ds Aq \(aq
+.el       .ds Aq '
+.\"
+.\" If the F register is >0, we'll generate index entries on stderr for
+.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
+.\" entries marked with X<> in POD.  Of course, you'll have to process the
+.\" output yourself in some meaningful fashion.
+.\"
+.\" Avoid warning from groff about undefined register 'F'.
+.de IX
+..
+.if !\nF .nr F 0
+.if \nF>0 \{\
+.    de IX
+.    tm Index:\\$1\t\\n%\t"\\$2"
+..
+.    if !\nF==2 \{\
+.        nr % 0
+.        nr F 2
+.    \}
+.\}
+.\"
+.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
+.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
+.    \" fudge factors for nroff and troff
+.if n \{\
+.    ds #H 0
+.    ds #V .8m
+.    ds #F .3m
+.    ds #[ \f1
+.    ds #] \fP
+.\}
+.if t \{\
+.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
+.    ds #V .6m
+.    ds #F 0
+.    ds #[ \&
+.    ds #] \&
+.\}
+.    \" simple accents for nroff and troff
+.if n \{\
+.    ds ' \&
+.    ds ` \&
+.    ds ^ \&
+.    ds , \&
+.    ds ~ ~
+.    ds /
+.\}
+.if t \{\
+.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
+.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
+.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
+.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
+.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
+.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
+.\}
+.    \" troff and (daisy-wheel) nroff accents
+.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
+.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
+.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
+.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
+.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
+.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
+.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
+.ds ae a\h'-(\w'a'u*4/10)'e
+.ds Ae A\h'-(\w'A'u*4/10)'E
+.    \" corrections for vroff
+.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
+.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
+.    \" for low resolution devices (crt and lpr)
+.if \n(.H>23 .if \n(.V>19 \
+\{\
+.    ds : e
+.    ds 8 ss
+.    ds o a
+.    ds d- d\h'-1'\(ga
+.    ds D- D\h'-1'\(hy
+.    ds th \o'bp'
+.    ds Th \o'LP'
+.    ds ae ae
+.    ds Ae AE
+.\}
+.rm #[ #] #H #V #F C
+.\" ========================================================================
+.\"
+.IX Title "DBFP_DEPARTURE_CLOSE 3"
+.TH DBFP_DEPARTURE_CLOSE 3 "2016-06-08" "0.1.0" "DB timetable API"
+.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
+.\" way too many mistakes in technical documents.
+.if n .ad l
+.nh
+.SH "NAME"
+dbfb_departure_close \- cleans up the data stored for a departure returned by
+the DB timetable API
+.SH "SYNOPSIS"
+.IX Header "SYNOPSIS"
+.Vb 1
+\&    #include <dbfp.h>
+\&
+\&    void dbfp_dparture_close(struct dbfp_dparture *departure);
+.Ve
+.SH "DESCRIPTION"
+.IX Header "DESCRIPTION"
+\&\fBdbfp_departure_close\fR cleans up a \fIdbfp_departure\fR structure and releases
+its allocated resources.  The structure itself is not freed.  \fIdeparture\fR
+may be \s-1NULL.\s0
+.SH "SEE ALSO"
+.IX Header "SEE ALSO"
+\&\fIdbfp_query_departure\fR\|(3)
diff --git a/man/dbfp_departure_close.pod b/man/dbfp_departure_close.pod
new file mode 100644
index 0000000..c18faca
--- /dev/null
+++ b/man/dbfp_departure_close.pod
@@ -0,0 +1,20 @@
+=head1 NAME
+
+dbfb_departure_close - cleans up the data stored for a departure returned by
+the DB timetable API
+
+=head1 SYNOPSIS
+
+    #include <dbfp.h>
+
+    void dbfp_dparture_close(struct dbfp_dparture *departure);
+
+=head1 DESCRIPTION
+
+B<dbfp_departure_close> cleans up a I<dbfp_departure> structure and releases
+its allocated resources.  The structure itself is not freed.  I<departure>
+may be NULL.
+
+=head1 SEE ALSO
+
+L<dbfp_query_departure(3)>
diff --git a/man/dbfp_init.3 b/man/dbfp_init.3
index 46a8a77..1632cc5 100644
--- a/man/dbfp_init.3
+++ b/man/dbfp_init.3
@@ -129,7 +129,7 @@
 .\" ========================================================================
 .\"
 .IX Title "DBFP_INIT 3"
-.TH DBFP_INIT 3 "2016-06-08" "0.1.0" "DB timetable API"
+.TH DBFP_INIT 3 "2016-06-10" "0.1.0" "DB timetable API"
 .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
 .\" way too many mistakes in technical documents.
 .if n .ad l
@@ -204,4 +204,4 @@ if curl could not be initialized
 .Ve
 .SH "SEE ALSO"
 .IX Header "SEE ALSO"
-\&\fIdbfp_close\fR\|(3)
+\&\fIdbfp_close\fR\|(3), \fIdbfp_query_departure\fR\|(3), \fIdbfp_query_location\fR\|(3)
diff --git a/man/dbfp_init.pod b/man/dbfp_init.pod
index 8749a2f..d94832f 100644
--- a/man/dbfp_init.pod
+++ b/man/dbfp_init.pod
@@ -75,4 +75,4 @@ if curl could not be initialized
 
 =head1 SEE ALSO
 
-L<dbfp_close(3)>
+L<dbfp_close(3)>, L<dbfp_query_departure(3)>, L<dbfp_query_location(3)>
diff --git a/man/dbfp_query_departure.3 b/man/dbfp_query_departure.3
new file mode 100644
index 0000000..b1e39f0
--- /dev/null
+++ b/man/dbfp_query_departure.3
@@ -0,0 +1,259 @@
+.\" Automatically generated by Pod::Man 4.07 (Pod::Simple 3.32)
+.\"
+.\" Standard preamble:
+.\" ========================================================================
+.de Sp \" Vertical space (when we can't use .PP)
+.if t .sp .5v
+.if n .sp
+..
+.de Vb \" Begin verbatim text
+.ft CW
+.nf
+.ne \\$1
+..
+.de Ve \" End verbatim text
+.ft R
+.fi
+..
+.\" Set up some character translations and predefined strings.  \*(-- will
+.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
+.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
+.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
+.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
+.\" nothing in troff, for use with C<>.
+.tr \(*W-
+.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
+.ie n \{\
+.    ds -- \(*W-
+.    ds PI pi
+.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
+.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
+.    ds L" ""
+.    ds R" ""
+.    ds C` ""
+.    ds C' ""
+'br\}
+.el\{\
+.    ds -- \|\(em\|
+.    ds PI \(*p
+.    ds L" ``
+.    ds R" ''
+.    ds C`
+.    ds C'
+'br\}
+.\"
+.\" Escape single quotes in literal strings from groff's Unicode transform.
+.ie \n(.g .ds Aq \(aq
+.el       .ds Aq '
+.\"
+.\" If the F register is >0, we'll generate index entries on stderr for
+.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
+.\" entries marked with X<> in POD.  Of course, you'll have to process the
+.\" output yourself in some meaningful fashion.
+.\"
+.\" Avoid warning from groff about undefined register 'F'.
+.de IX
+..
+.if !\nF .nr F 0
+.if \nF>0 \{\
+.    de IX
+.    tm Index:\\$1\t\\n%\t"\\$2"
+..
+.    if !\nF==2 \{\
+.        nr % 0
+.        nr F 2
+.    \}
+.\}
+.\"
+.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
+.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
+.    \" fudge factors for nroff and troff
+.if n \{\
+.    ds #H 0
+.    ds #V .8m
+.    ds #F .3m
+.    ds #[ \f1
+.    ds #] \fP
+.\}
+.if t \{\
+.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
+.    ds #V .6m
+.    ds #F 0
+.    ds #[ \&
+.    ds #] \&
+.\}
+.    \" simple accents for nroff and troff
+.if n \{\
+.    ds ' \&
+.    ds ` \&
+.    ds ^ \&
+.    ds , \&
+.    ds ~ ~
+.    ds /
+.\}
+.if t \{\
+.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
+.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
+.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
+.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
+.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
+.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
+.\}
+.    \" troff and (daisy-wheel) nroff accents
+.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
+.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
+.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
+.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
+.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
+.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
+.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
+.ds ae a\h'-(\w'a'u*4/10)'e
+.ds Ae A\h'-(\w'A'u*4/10)'E
+.    \" corrections for vroff
+.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
+.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
+.    \" for low resolution devices (crt and lpr)
+.if \n(.H>23 .if \n(.V>19 \
+\{\
+.    ds : e
+.    ds 8 ss
+.    ds o a
+.    ds d- d\h'-1'\(ga
+.    ds D- D\h'-1'\(hy
+.    ds th \o'bp'
+.    ds Th \o'LP'
+.    ds ae ae
+.    ds Ae AE
+.\}
+.rm #[ #] #H #V #F C
+.\" ========================================================================
+.\"
+.IX Title "DBFP_QUERY_DEPARTURE 3"
+.TH DBFP_QUERY_DEPARTURE 3 "2016-06-10" "0.1.0" "DB timetable API"
+.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
+.\" way too many mistakes in technical documents.
+.if n .ad l
+.nh
+.SH "NAME"
+dbfp_query_departure \- get a list of departures at a given station from the
+DB timetable API
+.SH "SYNOPSIS"
+.IX Header "SYNOPSIS"
+.Vb 1
+\&    #include <dbfp.h>
+\&
+\&    int dbfp_query_departure(struct dbfp *dbfp, char *location_id, time_t time,
+\&                    size_t *n, struct dbfp_departure **departures);
+.Ve
+.SH "DESCRIPTION"
+.IX Header "DESCRIPTION"
+\&\fBdbfp_query_departure\fR queries a list of departures at a the station with the
+given \fIlocation_id\fR at the given \fItime\fR using the connection metadata stored
+in \fIdbfp\fR.  The number of results is stored in \fIn\fR.  The results are stored
+in \fIdepartures\fR.  The memory for the \fIdepartures\fR is allocated by the
+function.  The stored array contains exactly \fIn\fR elements, and is not \s-1NULL\s0
+terminated.
+.PP
+Possible values for \fIlocation_id\fR can be retrieved using
+\&\fIdbfp_query_location\fR.  If \fItime\fR is zero, the current time is used.
+\&\fIdbfp\fR, \fIlocation_id\fR, \fIn\fR and \fIdepartures\fR must not be \s-1NULL. \s0\fIdbfp\fR must
+have been initialized with \fIdbfp_init\fR.  The elements in \fIdepartures\fR should
+be closed with \fIdbfp_departure_close\fR.  \fIdepartures\fR should be freed by the
+caller.
+.PP
+If the query fails, the values of \fIn\fR and \fIdepartures\fR are set to 0 and \s-1NULL\s0
+respectively.
+.PP
+The \fBdbfp_departure\fR structure is defined as:
+.PP
+.Vb 9
+\&    struct dbfp_departure {
+\&            char *name;
+\&            char *type;
+\&            char *stopid;
+\&            char *stop;
+\&            time_t time;
+\&            char *direction;
+\&            char *track;
+\&    };
+.Ve
+.PP
+\&\fIname\fR is the name of the departing train, \fItype\fR is the type of the train.
+\&\fIstopid\fR is the \s-1ID\s0 of the stop the train departs from, and \fIstop\fR is its
+name.  \fItime\fR is the departure time, \fIdirection\fR the direction of the train,
+and \fItrack\fR the departure track.
+.SH "RETURN VALUE"
+.IX Header "RETURN VALUE"
+\&\fBdbfp_query_departure\fR returns zero if successful, or a non-zero error code.
+Positive error codes are from \fIerrno.h\fR, negative error codes are specific
+to dbfp.
+.SH "ERRORS"
+.IX Header "ERRORS"
+.IP "\s-1EINVAL\s0" 4
+.IX Item "EINVAL"
+if \fIdbfp\fR, \fIlocation_id\fR, \fIn\fR or \fIdepartures\fR is \s-1NULL\s0
+.IP "\s-1ENOMEM\s0" 4
+.IX Item "ENOMEM"
+if there is not enough memory to store the results of the query
+.IP "\s-1DBFP_ERROR_CURL\s0" 4
+.IX Item "DBFP_ERROR_CURL"
+if an error occured during the preparation or execution of the network request
+.IP "\s-1DBFP_ERROR_FORMAT\s0" 4
+.IX Item "DBFP_ERROR_FORMAT"
+if an error occurs during the formatting of the \s-1URL\s0
+.IP "\s-1DBFP_ERROR_PARSE\s0" 4
+.IX Item "DBFP_ERROR_PARSE"
+if an error occurs during the parsing of the \s-1XML\s0 response
+.IP "\s-1DBFP_ERROR_STRUCTURE\s0" 4
+.IX Item "DBFP_ERROR_STRUCTURE"
+if the \s-1API\s0 response has not the expected structure
+.SH "BUGS"
+.IX Header "BUGS"
+Due to a typo in the \s-1DB\s0 timetable \s-1API,\s0 the \fItype\fR field of one or more of the
+\&\fIdepartures\fR elements might be \s-1NULL.\s0
+.PP
+The time zone handling has to be checked and documented.
+.SH "EXAMPLE"
+.IX Header "EXAMPLE"
+.Vb 4
+\&    #include <dbfp.h>
+\&    #include <stdio.h>
+\&    #include <stdlib.h>
+\&    #include <string.h>
+\&
+\&    int main(int argc, char **argv)
+\&    {
+\&            int err = 0;
+\&            struct dbfp dbfp;
+\&            struct dbfp_departure *departures = NULL;
+\&            size_t n = 0;
+\&            size_t i;
+\&
+\&            err = dbfp_init(&dbfp, "API key");
+\&            if (err)
+\&                    goto cleanup;
+\&            err = dbfp_query_departure(&dbfp, "8000105", 0, &n, &departures);
+\&            if (err)
+\&                    goto cleanup;
+\&
+\&            printf("Number of matches: %zu\en", n);
+\&            if (n > 0)
+\&                    printf("Departures from %s:\en", departures[0].stop);
+\&            for (i = 0; i < n; i++)
+\&                    printf("%s to %s from track %s\en", departures[i].name,
+\&                                    departures[i].direction, departures[i].track);
+\&
+\&    cleanup:
+\&            if (err)
+\&                    printf("An error occured: %s\en", strerror(err));
+\&            for (i = 0; i < n; i++)
+\&                    dbfp_departure_close(&departures[i]);
+\&            free(departures);
+\&            dbfp_close(&dbfp);
+\&
+\&            return err ? EXIT_FAILURE : EXIT_SUCCESS;
+\&    }
+.Ve
+.SH "SEE ALSO"
+.IX Header "SEE ALSO"
+\&\fIdbfp_init\fR\|(3), \fIdbfp_departure_close\fR\|(3)
diff --git a/man/dbfp_query_departure.pod b/man/dbfp_query_departure.pod
new file mode 100644
index 0000000..0fcae28
--- /dev/null
+++ b/man/dbfp_query_departure.pod
@@ -0,0 +1,134 @@
+=head1 NAME
+
+dbfp_query_departure - get a list of departures at a given station from the
+DB timetable API
+
+=head1 SYNOPSIS
+
+    #include <dbfp.h>
+
+    int dbfp_query_departure(struct dbfp *dbfp, char *location_id, time_t time,
+                    size_t *n, struct dbfp_departure **departures);
+
+=head1 DESCRIPTION
+
+B<dbfp_query_departure> queries a list of departures at a the station with the
+given I<location_id> at the given I<time> using the connection metadata stored
+in I<dbfp>.  The number of results is stored in I<n>.  The results are stored
+in I<departures>.  The memory for the I<departures> is allocated by the
+function.  The stored array contains exactly I<n> elements, and is not NULL
+terminated.
+
+Possible values for I<location_id> can be retrieved using
+I<dbfp_query_location>.  If I<time> is zero, the current time is used.
+I<dbfp>, I<location_id>, I<n> and I<departures> must not be NULL. I<dbfp> must
+have been initialized with I<dbfp_init>.  The elements in I<departures> should
+be closed with I<dbfp_departure_close>.  I<departures> should be freed by the
+caller.
+
+If the query fails, the values of I<n> and I<departures> are set to 0 and NULL
+respectively.
+
+The B<dbfp_departure> structure is defined as:
+
+    struct dbfp_departure {
+            char *name;
+            char *type;
+            char *stopid;
+            char *stop;
+            time_t time;
+            char *direction;
+            char *track;
+    };
+
+I<name> is the name of the departing train, I<type> is the type of the train.
+I<stopid> is the ID of the stop the train departs from, and I<stop> is its
+name.  I<time> is the departure time, I<direction> the direction of the train,
+and I<track> the departure track.
+
+=head1 RETURN VALUE
+
+B<dbfp_query_departure> returns zero if successful, or a non-zero error code.
+Positive error codes are from I<errno.h>, negative error codes are specific
+to dbfp.
+
+=head1 ERRORS
+
+=over
+
+=item EINVAL
+
+if I<dbfp>, I<location_id>, I<n> or I<departures> is NULL
+
+=item ENOMEM
+
+if there is not enough memory to store the results of the query
+
+=item DBFP_ERROR_CURL
+
+if an error occured during the preparation or execution of the network request
+
+=item DBFP_ERROR_FORMAT
+
+if an error occurs during the formatting of the URL
+
+=item DBFP_ERROR_PARSE
+
+if an error occurs during the parsing of the XML response
+
+=item DBFP_ERROR_STRUCTURE
+
+if the API response has not the expected structure
+
+=back
+
+=head1 BUGS
+
+Due to a typo in the DB timetable API, the I<type> field of one or more of the
+I<departures> elements might be NULL.
+
+The time zone handling has to be checked and documented.
+
+=head1 EXAMPLE
+
+    #include <dbfp.h>
+    #include <stdio.h>
+    #include <stdlib.h>
+    #include <string.h>
+
+    int main(int argc, char **argv)
+    {
+            int err = 0;
+            struct dbfp dbfp;
+            struct dbfp_departure *departures = NULL;
+            size_t n = 0;
+            size_t i;
+
+            err = dbfp_init(&dbfp, "API key");
+            if (err)
+                    goto cleanup;
+            err = dbfp_query_departure(&dbfp, "8000105", 0, &n, &departures);
+            if (err)
+                    goto cleanup;
+
+            printf("Number of matches: %zu\n", n);
+            if (n > 0)
+                    printf("Departures from %s:\n", departures[0].stop);
+            for (i = 0; i < n; i++)
+                    printf("%s to %s from track %s\n", departures[i].name,
+                                    departures[i].direction, departures[i].track);
+
+    cleanup:
+            if (err)
+                    printf("An error occured: %s\n", strerror(err));
+            for (i = 0; i < n; i++)
+                    dbfp_departure_close(&departures[i]);
+            free(departures);
+            dbfp_close(&dbfp);
+
+            return err ? EXIT_FAILURE : EXIT_SUCCESS;
+    }
+
+=head1 SEE ALSO
+
+L<dbfp_init(3)>, L<dbfp_departure_close(3)>