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	16
	17	<H1><A NAME="SEC7" HREF="gettext_toc.html#TOC7">PO Files and PO Mode Basics</A></H1>
	18
	19	<P>
	20	The GNU <CODE>gettext</CODE> toolset helps programmers and translators
	21	at producing, updating and using translation files, mainly those
	22	PO files which are textual, editable files. This chapter stresses
	23	the format of PO files, and contains a PO mode starter. PO mode
	24	description is spread throughout this manual instead of being concentrated
	25	in one place. Here we present only the basics of PO mode.
	26
	27	</P>
	28
	29
	30
	31	<H2><A NAME="SEC8" HREF="gettext_toc.html#TOC8">Completing GNU <CODE>gettext</CODE> Installation</A></H2>
	32
	33	<P>
	34	Once you have received, unpacked, configured and compiled the GNU
	35	<CODE>gettext</CODE> distribution, the <SAMP>`make install'</SAMP> command puts in
	36	place the programs <CODE>xgettext</CODE>, <CODE>msgfmt</CODE>, <CODE>gettext</CODE>, and
	37	<CODE>msgmerge</CODE>, as well as their available message catalogs. To
	38	top off a comfortable installation, you might also want to make the
	39	PO mode available to your GNU Emacs users.
	40
	41	</P>
	42	<P>
	43	During the installation of the PO mode, you might want modify your
	44	file <TT>`.emacs'</TT>, once and for all, so it contains a few lines looking
	45	like:
	46
	47	</P>
	48
	49	<PRE>
	50	(setq auto-mode-alist
	51	(cons '("\\.po[tx]?\\'\\\|\\.po\\." . po-mode) auto-mode-alist))
	52	(autoload 'po-mode "po-mode")
	53	</PRE>
	54
	55	<P>
	56	Later, whenever you edit some <TT>`.po'</TT>, <TT>`.pot'</TT> or <TT>`.pox'</TT>
	57	file, or any file having the string <SAMP>`.po.'</SAMP> within its name,
	58	Emacs loads <TT>`po-mode.elc'</TT> (or <TT>`po-mode.el'</TT>) as needed, and
	59	automatically activates PO mode commands for the associated buffer.
	60	The string <EM>PO</EM> appears in the mode line for any buffer for
	61	which PO mode is active. Many PO files may be active at once in a
	62	single Emacs session.
	63
	64	</P>
	65	<P>
	66	If you are using Emacs version 20 or better, and have already installed
	67	the appropriate international fonts on your system, you may also manage
	68	for the these fonts to be automatically loaded and used for displaying
	69	the translations on your Emacs screen, whenever necessary. For this to
	70	happen, you might want to add the lines:
	71
	72	</P>
	73
	74	<PRE>
	75	(autoload 'po-find-file-coding-system "po-mode")
	76	(modify-coding-system-alist 'file "\\.po[tx]?\\'\\\|\\.po\\."
	77	'po-find-file-coding-system)
	78	</PRE>
	79
	80	<P>
	81	to your <TT>`.emacs'</TT> file.
	82
	83	</P>
	84
	85
	86	<H2><A NAME="SEC9" HREF="gettext_toc.html#TOC9">The Format of PO Files</A></H2>
	87
	88	<P>
	89	A PO file is made up of many entries, each entry holding the relation
	90	between an original untranslated string and its corresponding
	91	translation. All entries in a given PO file usually pertain
	92	to a single project, and all translations are expressed in a single
	93	target language. One PO file <STRONG>entry</STRONG> has the following schematic
	94	structure:
	95
	96	</P>
	97
	98	<PRE>
	99	<VAR>white-space</VAR>
	100	# <VAR>translator-comments</VAR>
	101	#. <VAR>automatic-comments</VAR>
	102	#: <VAR>reference</VAR>...
	103	#, <VAR>flag</VAR>...
	104	msgid <VAR>untranslated-string</VAR>
	105	msgstr <VAR>translated-string</VAR>
	106	</PRE>
	107
	108	<P>
	109	The general structure of a PO file should be well understood by
	110	the translator. When using PO mode, very little has to be known
	111	about the format details, as PO mode takes care of them for her.
	112
	113	</P>
	114	<P>
	115	Entries begin with some optional white space. Usually, when generated
	116	through GNU <CODE>gettext</CODE> tools, there is exactly one blank line
	117	between entries. Then comments follow, on lines all starting with the
	118	character <KBD>#</KBD>. There are two kinds of comments: those which have
	119	some white space immediately following the <KBD>#</KBD>, which comments are
	120	created and maintained exclusively by the translator, and those which
	121	have some non-white character just after the <KBD>#</KBD>, which comments
	122	are created and maintained automatically by GNU <CODE>gettext</CODE> tools.
	123	All comments, of either kind, are optional.
	124
	125	</P>
	126	<P>
	127	After white space and comments, entries show two strings, giving
	128	first the untranslated string as it appears in the original program
	129	sources, and then, the translation of this string. The original
	130	string is introduced by the keyword <CODE>msgid</CODE>, and the translation,
	131	by <CODE>msgstr</CODE>. The two strings, untranslated and translated,
	132	are quoted in various ways in the PO file, using <KBD>"</KBD>
	133	delimiters and <KBD>\</KBD> escapes, but the translator does not really
	134	have to pay attention to the precise quoting format, as PO mode fully
	135	intend to take care of quoting for her.
	136
	137	</P>
	138	<P>
	139	The <CODE>msgid</CODE> strings, as well as automatic comments, are produced
	140	and managed by other GNU <CODE>gettext</CODE> tools, and PO mode does not
	141	provide means for the translator to alter these. The most she can
	142	do is merely deleting them, and only by deleting the whole entry.
	143	On the other hand, the <CODE>msgstr</CODE> string, as well as translator
	144	comments, are really meant for the translator, and PO mode gives her
	145	the full control she needs.
	146
	147	</P>
	148	<P>
	149	The comment lines beginning with <KBD>#,</KBD> are special because they are
	150	not completely ignored by the programs as comments generally are. The
	151	comma separated list of <VAR>flag</VAR>s is used by the <CODE>msgfmt</CODE>
	152	program to give the user some better diagnostic messages. Currently
	153	there are two forms of flags defined:
	154
	155	</P>
	156	<DL COMPACT>
	157
	158	<DT><KBD>fuzzy</KBD>
	159	<DD>
	160	This flag can be generated by the <CODE>msgmerge</CODE> program or it can be
	161	inserted by the translator herself. It shows that the <CODE>msgstr</CODE>
	162	string might not be a correct translation (anymore). Only the translator
	163	can judge if the translation requires further modification, or is
	164	acceptable as is. Once satisfied with the translation, she then removes
	165	this <KBD>fuzzy</KBD> attribute. The <CODE>msgmerge</CODE> programs inserts this
	166	when it combined the <CODE>msgid</CODE> and <CODE>msgstr</CODE> entries after fuzzy
	167	search only. See section <A HREF="gettext_5.html#SEC26">Fuzzy Entries</A>.
	168
	169	<DT><KBD>c-format</KBD>
	170	<DD>
	171	<DT><KBD>no-c-format</KBD>
	172	<DD>
	173	These flags should not be added by a human. Instead only the
	174	<CODE>xgettext</CODE> program adds them. In an automated PO file processing
	175	system as proposed here the user changes would be thrown away again as
	176	soon as the <CODE>xgettext</CODE> program generates a new template file.
	177
	178	In case the <KBD>c-format</KBD> flag is given for a string the <CODE>msgfmt</CODE>
	179	does some more tests to check to validity of the translation.
	180	See section <A HREF="gettext_6.html#SEC33">Invoking the <CODE>msgfmt</CODE> Program</A>.
	181
	182	</DL>
	183
	184	<P>
	185	It happens that some lines, usually whitespace or comments, follow the
	186	very last entry of a PO file. Such lines are not part of any entry,
	187	and PO mode is unable to take action on those lines. By using the
	188	PO mode function <KBD>M-x po-normalize</KBD>, the translator may get
	189	rid of those spurious lines. See section <A HREF="gettext_2.html#SEC12">Normalizing Strings in Entries</A>.
	190
	191	</P>
	192	<P>
	193	The remainder of this section may be safely skipped by those using
	194	PO mode, yet it may be interesting for everybody to have a better
	195	idea of the precise format of a PO file. On the other hand, those
	196	not having GNU Emacs handy should carefully continue reading on.
	197
	198	</P>
	199	<P>
	200	Each of <VAR>untranslated-string</VAR> and <VAR>translated-string</VAR> respects
	201	the C syntax for a character string, including the surrounding quotes
	202	and embedded backslashed escape sequences. When the time comes
	203	to write multi-line strings, one should not use escaped newlines.
	204	Instead, a closing quote should follow the last character on the
	205	line to be continued, and an opening quote should resume the string
	206	at the beginning of the following PO file line. For example:
	207
	208	</P>
	209
	210	<PRE>
	211	msgid ""
	212	"Here is an example of how one might continue a very long string\n"
	213	"for the common case the string represents multi-line output.\n"
	214	</PRE>
	215
	216	<P>
	217	In this example, the empty string is used on the first line, to
	218	allow better alignment of the <KBD>H</KBD> from the word <SAMP>`Here'</SAMP>
	219	over the <KBD>f</KBD> from the word <SAMP>`for'</SAMP>. In this example, the
	220	<CODE>msgid</CODE> keyword is followed by three strings, which are meant
	221	to be concatenated. Concatenating the empty string does not change
	222	the resulting overall string, but it is a way for us to comply with
	223	the necessity of <CODE>msgid</CODE> to be followed by a string on the same
	224	line, while keeping the multi-line presentation left-justified, as
	225	we find this to be a cleaner disposition. The empty string could have
	226	been omitted, but only if the string starting with <SAMP>`Here'</SAMP> was
	227	promoted on the first line, right after <CODE>msgid</CODE>.<A NAME="DOCF1" HREF="gettext_foot.html#FOOT1">(1)</A> It was not really necessary
	228	either to switch between the two last quoted strings immediately after
	229	the newline <SAMP>`\n'</SAMP>, the switch could have occurred after <EM>any</EM>
	230	other character, we just did it this way because it is neater.
	231
	232	</P>
	233	<P>
	234	One should carefully distinguish between end of lines marked as
	235	<SAMP>`\n'</SAMP> <EM>inside</EM> quotes, which are part of the represented
	236	string, and end of lines in the PO file itself, outside string quotes,
	237	which have no incidence on the represented string.
	238
	239	</P>
	240	<P>
	241	Outside strings, white lines and comments may be used freely.
	242	Comments start at the beginning of a line with <SAMP>`#'</SAMP> and extend
	243	until the end of the PO file line. Comments written by translators
	244	should have the initial <SAMP>`#'</SAMP> immediately followed by some white
	245	space. If the <SAMP>`#'</SAMP> is not immediately followed by white space,
	246	this comment is most likely generated and managed by specialized GNU
	247	tools, and might disappear or be replaced unexpectedly when the PO
	248	file is given to <CODE>msgmerge</CODE>.
	249
	250	</P>
	251
	252
	253	<H2><A NAME="SEC10" HREF="gettext_toc.html#TOC10">Main PO mode Commands</A></H2>
	254
	255	<P>
	256	After setting up Emacs with something similar to the lines in
	257	section <A HREF="gettext_2.html#SEC8">Completing GNU <CODE>gettext</CODE> Installation</A>, PO mode is activated for a window when Emacs finds a
	258	PO file in that window. This puts the window read-only and establishes a
	259	po-mode-map, which is a genuine Emacs mode, in a way that is not derived
	260	from text mode in any way. Functions found on <CODE>po-mode-hook</CODE>,
	261	if any, will be executed.
	262
	263	</P>
	264	<P>
	265	When PO mode is active in a window, the letters <SAMP>`PO'</SAMP> appear
	266	in the mode line for that window. The mode line also displays how
	267	many entries of each kind are held in the PO file. For example,
	268	the string <SAMP>`132t+3f+10u+2o'</SAMP> would tell the translator that the
	269	PO mode contains 132 translated entries (see section <A HREF="gettext_5.html#SEC25">Translated Entries</A>,
	270	3 fuzzy entries (see section <A HREF="gettext_5.html#SEC26">Fuzzy Entries</A>), 10 untranslated entries
	271	(see section <A HREF="gettext_5.html#SEC27">Untranslated Entries</A>) and 2 obsolete entries (see section <A HREF="gettext_5.html#SEC28">Obsolete Entries</A>). Zero-coefficients items are not shown. So, in this example, if
	272	the fuzzy entries were unfuzzied, the untranslated entries were translated
	273	and the obsolete entries were deleted, the mode line would merely display
	274	<SAMP>`145t'</SAMP> for the counters.
	275
	276	</P>
	277	<P>
	278	The main PO commands are those which do not fit into the other categories of
	279	subsequent sections. These allow for quitting PO mode or for managing windows
	280	in special ways.
	281
	282	</P>
	283	<DL COMPACT>
	284
	285	<DT><KBD>U</KBD>
	286	<DD>
	287	Undo last modification to the PO file.
	288
	289	<DT><KBD>Q</KBD>
	290	<DD>
	291	Quit processing and save the PO file.
	292
	293	<DT><KBD>q</KBD>
	294	<DD>
	295	Quit processing, possibly after confirmation.
	296
	297	<DT><KBD>O</KBD>
	298	<DD>
	299	Temporary leave the PO file window.
	300
	301	<DT><KBD>?</KBD>
	302	<DD>
	303	<DT><KBD>h</KBD>
	304	<DD>
	305	Show help about PO mode.
	306
	307	<DT><KBD>=</KBD>
	308	<DD>
	309	Give some PO file statistics.
	310
	311	<DT><KBD>V</KBD>
	312	<DD>
	313	Batch validate the format of the whole PO file.
	314
	315	</DL>
	316
	317	<P>
	318	The command <KBD>U</KBD> (<CODE>po-undo</CODE>) interfaces to the GNU Emacs
	319	<EM>undo</EM> facility. See section `Undoing Changes' in <CITE>The Emacs Editor</CITE>. Each time <KBD>U</KBD> is typed, modifications which the translator
	320	did to the PO file are undone a little more. For the purpose of
	321	undoing, each PO mode command is atomic. This is especially true for
	322	the <KBD><KBD>RET</KBD></KBD> command: the whole edition made by using a single
	323	use of this command is undone at once, even if the edition itself
	324	implied several actions. However, while in the editing window, one
	325	can undo the edition work quite parsimoniously.
	326
	327	</P>
	328	<P>
	329	The commands <KBD>Q</KBD> (<CODE>po-quit</CODE>) and <KBD>q</KBD>
	330	(<CODE>po-confirm-and-quit</CODE>) are used when the translator is done with the
	331	PO file. The former is a bit less verbose than the latter. If the file
	332	has been modified, it is saved to disk first. In both cases, and prior to
	333	all this, the commands check if some untranslated message remains in the
	334	PO file and, if yes, the translator is asked if she really wants to leave
	335	off working with this PO file. This is the preferred way of getting rid
	336	of an Emacs PO file buffer. Merely killing it through the usual command
	337	<KBD>C-x k</KBD> (<CODE>kill-buffer</CODE>) is not the tidiest way to proceed.
	338
	339	</P>
	340	<P>
	341	The command <KBD>O</KBD> (<CODE>po-other-window</CODE>) is another, softer way,
	342	to leave PO mode, temporarily. It just moves the cursor to some other
	343	Emacs window, and pops one if necessary. For example, if the translator
	344	just got PO mode to show some source context in some other, she might
	345	discover some apparent bug in the program source that needs correction.
	346	This command allows the translator to change sex, become a programmer,
	347	and have the cursor right into the window containing the program she
	348	(or rather <EM>he</EM>) wants to modify. By later getting the cursor back
	349	in the PO file window, or by asking Emacs to edit this file once again,
	350	PO mode is then recovered.
	351
	352	</P>
	353	<P>
	354	The command <KBD>h</KBD> (<CODE>po-help</CODE>) displays a summary of all available PO
	355	mode commands. The translator should then type any character to resume
	356	normal PO mode operations. The command <KBD>?</KBD> has the same effect
	357	as <KBD>h</KBD>.
	358
	359	</P>
	360	<P>
	361	The command <KBD>=</KBD> (<CODE>po-statistics</CODE>) computes the total number of
	362	entries in the PO file, the ordinal of the current entry (counted from
	363	1), the number of untranslated entries, the number of obsolete entries,
	364	and displays all these numbers.
	365
	366	</P>
	367	<P>
	368	The command <KBD>V</KBD> (<CODE>po-validate</CODE>) launches <CODE>msgfmt</CODE> in verbose
	369	mode over the current PO file. This command first offers to save the
	370	current PO file on disk. The <CODE>msgfmt</CODE> tool, from GNU <CODE>gettext</CODE>,
	371	has the purpose of creating a MO file out of a PO file, and PO mode uses
	372	the features of this program for checking the overall format of a PO file,
	373	as well as all individual entries.
	374
	375	</P>
	376	<P>
	377	The program <CODE>msgfmt</CODE> runs asynchronously with Emacs, so the
	378	translator regains control immediately while her PO file is being studied.
	379	Error output is collected in the GNU Emacs <SAMP>`compilation'</SAMP> buffer,
	380	displayed in another window. The regular GNU Emacs command <KBD>C-x`</KBD>
	381	(<CODE>next-error</CODE>), as well as other usual compile commands, allow the
	382	translator to reposition quickly to the offending parts of the PO file.
	383	Once the cursor is on the line in error, the translator may decide on
	384	any PO mode action which would help correcting the error.
	385
	386	</P>
	387
	388
	389	<H2><A NAME="SEC11" HREF="gettext_toc.html#TOC11">Entry Positioning</A></H2>
	390
	391	<P>
	392	The cursor in a PO file window is almost always part of
	393	an entry. The only exceptions are the special case when the cursor
	394	is after the last entry in the file, or when the PO file is
	395	empty. The entry where the cursor is found to be is said to be the
	396	current entry. Many PO mode commands operate on the current entry,
	397	so moving the cursor does more than allowing the translator to browse
	398	the PO file, this also selects on which entry commands operate.
	399
	400	</P>
	401	<P>
	402	Some PO mode commands alter the position of the cursor in a specialized
	403	way. A few of those special purpose positioning are described here,
	404	the others are described in following sections.
	405
	406	</P>
	407	<DL COMPACT>
	408
	409	<DT><KBD>.</KBD>
	410	<DD>
	411	Redisplay the current entry.
	412
	413	<DT><KBD>n</KBD>
	414	<DD>
	415	<DT><KBD>n</KBD>
	416	<DD>
	417	Select the entry after the current one.
	418
	419	<DT><KBD>p</KBD>
	420	<DD>
	421	<DT><KBD>p</KBD>
	422	<DD>
	423	Select the entry before the current one.
	424
	425	<DT><KBD><</KBD>
	426	<DD>
	427	Select the first entry in the PO file.
	428
	429	<DT><KBD>></KBD>
	430	<DD>
	431	Select the last entry in the PO file.
	432
	433	<DT><KBD>m</KBD>
	434	<DD>
	435	Record the location of the current entry for later use.
	436
	437	<DT><KBD>l</KBD>
	438	<DD>
	439	Return to a previously saved entry location.
	440
	441	<DT><KBD>x</KBD>
	442	<DD>
	443	Exchange the current entry location with the previously saved one.
	444
	445	</DL>
	446
	447	<P>
	448	Any GNU Emacs command able to reposition the cursor may be used
	449	to select the current entry in PO mode, including commands which
	450	move by characters, lines, paragraphs, screens or pages, and search
	451	commands. However, there is a kind of standard way to display the
	452	current entry in PO mode, which usual GNU Emacs commands moving
	453	the cursor do not especially try to enforce. The command <KBD>.</KBD>
	454	(<CODE>po-current-entry</CODE>) has the sole purpose of redisplaying the
	455	current entry properly, after the current entry has been changed by
	456	means external to PO mode, or the Emacs screen otherwise altered.
	457
	458	</P>
	459	<P>
	460	It is yet to be decided if PO mode helps the translator, or otherwise
	461	irritates her, by forcing a rigid window disposition while she
	462	is doing her work. We originally had quite precise ideas about
	463	how windows should behave, but on the other hand, anyone used to
	464	GNU Emacs is often happy to keep full control. Maybe a fixed window
	465	disposition might be offered as a PO mode option that the translator
	466	might activate or deactivate at will, so it could be offered on an
	467	experimental basis. If nobody feels a real need for using it, or
	468	a compulsion for writing it, we should drop this whole idea.
	469	The incentive for doing it should come from translators rather than
	470	programmers, as opinions from an experienced translator are surely
	471	more worth to me than opinions from programmers <EM>thinking</EM> about
	472	how <EM>others</EM> should do translation.
	473
	474	</P>
	475	<P>
	476	The commands <KBD>n</KBD> (<CODE>po-next-entry</CODE>) and <KBD>p</KBD>
	477	(<CODE>po-previous-entry</CODE>) move the cursor the entry following,
	478	or preceding, the current one. If <KBD>n</KBD> is given while the
	479	cursor is on the last entry of the PO file, or if <KBD>p</KBD>
	480	is given while the cursor is on the first entry, no move is done.
	481
	482	</P>
	483	<P>
	484	The commands <KBD><</KBD> (<CODE>po-first-entry</CODE>) and <KBD>></KBD>
	485	(<CODE>po-last-entry</CODE>) move the cursor to the first entry, or last
	486	entry, of the PO file. When the cursor is located past the last
	487	entry in a PO file, most PO mode commands will return an error saying
	488	<SAMP>`After last entry'</SAMP>. Moreover, the commands <KBD><</KBD> and <KBD>></KBD>
	489	have the special property of being able to work even when the cursor
	490	is not into some PO file entry, and one may use them for nicely
	491	correcting this situation. But even these commands will fail on a
	492	truly empty PO file. There are development plans for the PO mode for it
	493	to interactively fill an empty PO file from sources. See section <A HREF="gettext_3.html#SEC16">Marking Translatable Strings</A>.
	494
	495	</P>
	496	<P>
	497	The translator may decide, before working at the translation of
	498	a particular entry, that she needs to browse the remainder of the
	499	PO file, maybe for finding the terminology or phraseology used
	500	in related entries. She can of course use the standard Emacs idioms
	501	for saving the current cursor location in some register, and use that
	502	register for getting back, or else, use the location ring.
	503
	504	</P>
	505	<P>
	506	PO mode offers another approach, by which cursor locations may be saved
	507	onto a special stack. The command <KBD>m</KBD> (<CODE>po-push-location</CODE>)
	508	merely adds the location of current entry to the stack, pushing
	509	the already saved locations under the new one. The command
	510	<KBD>r</KBD> (<CODE>po-pop-location</CODE>) consumes the top stack element and
	511	reposition the cursor to the entry associated with that top element.
	512	This position is then lost, for the next <KBD>r</KBD> will move the cursor
	513	to the previously saved location, and so on until no locations remain
	514	on the stack.
	515
	516	</P>
	517	<P>
	518	If the translator wants the position to be kept on the location stack,
	519	maybe for taking a look at the entry associated with the top
	520	element, then go elsewhere with the intent of getting back later, she
	521	ought to use <KBD>m</KBD> immediately after <KBD>r</KBD>.
	522
	523	</P>
	524	<P>
	525	The command <KBD>x</KBD> (<CODE>po-exchange-location</CODE>) simultaneously
	526	reposition the cursor to the entry associated with the top element of
	527	the stack of saved locations, and replace that top element with the
	528	location of the current entry before the move. Consequently, repeating
	529	the <KBD>x</KBD> command toggles alternatively between two entries.
	530	For achieving this, the translator will position the cursor on the
	531	first entry, use <KBD>m</KBD>, then position to the second entry, and
	532	merely use <KBD>x</KBD> for making the switch.
	533
	534	</P>
	535
	536
	537	<H2><A NAME="SEC12" HREF="gettext_toc.html#TOC12">Normalizing Strings in Entries</A></H2>
	538
	539	<P>
	540	There are many different ways for encoding a particular string into a
	541	PO file entry, because there are so many different ways to split and
	542	quote multi-line strings, and even, to represent special characters
	543	by backslashed escaped sequences. Some features of PO mode rely on
	544	the ability for PO mode to scan an already existing PO file for a
	545	particular string encoded into the <CODE>msgid</CODE> field of some entry.
	546	Even if PO mode has internally all the built-in machinery for
	547	implementing this recognition easily, doing it fast is technically
	548	difficult. To facilitate a solution to this efficiency problem,
	549	we decided on a canonical representation for strings.
	550
	551	</P>
	552	<P>
	553	A conventional representation of strings in a PO file is currently
	554	under discussion, and PO mode experiments with a canonical representation.
	555	Having both <CODE>xgettext</CODE> and PO mode converging towards a uniform
	556	way of representing equivalent strings would be useful, as the internal
	557	normalization needed by PO mode could be automatically satisfied
	558	when using <CODE>xgettext</CODE> from GNU <CODE>gettext</CODE>. An explicit
	559	PO mode normalization should then be only necessary for PO files
	560	imported from elsewhere, or for when the convention itself evolves.
	561
	562	</P>
	563	<P>
	564	So, for achieving normalization of at least the strings of a given
	565	PO file needing a canonical representation, the following PO mode
	566	command is available:
	567
	568	</P>
	569	<DL COMPACT>
	570
	571	<DT><KBD>M-x po-normalize</KBD>
	572	<DD>
	573	Tidy the whole PO file by making entries more uniform.
	574
	575	</DL>
	576
	577	<P>
	578	The special command <KBD>M-x po-normalize</KBD>, which has no associate
	579	keys, revises all entries, ensuring that strings of both original
	580	and translated entries use uniform internal quoting in the PO file.
	581	It also removes any crumb after the last entry. This command may be
	582	useful for PO files freshly imported from elsewhere, or if we ever
	583	improve on the canonical quoting format we use. This canonical format
	584	is not only meant for getting cleaner PO files, but also for greatly
	585	speeding up <CODE>msgid</CODE> string lookup for some other PO mode commands.
	586
	587	</P>
	588	<P>
	589	<KBD>M-x po-normalize</KBD> presently makes three passes over the entries.
	590	The first implements heuristics for converting PO files for GNU
	591	<CODE>gettext</CODE> 0.6 and earlier, in which <CODE>msgid</CODE> and <CODE>msgstr</CODE>
	592	fields were using K&R style C string syntax for multi-line strings.
	593	These heuristics may fail for comments not related to obsolete
	594	entries and ending with a backslash; they also depend on subsequent
	595	passes for finalizing the proper commenting of continued lines for
	596	obsolete entries. This first pass might disappear once all oldish PO
	597	files would have been adjusted. The second and third pass normalize
	598	all <CODE>msgid</CODE> and <CODE>msgstr</CODE> strings respectively. They also
	599	clean out those trailing backslashes used by XView's <CODE>msgfmt</CODE>
	600	for continued lines.
	601
	602	</P>
	603	<P>
	604	Having such an explicit normalizing command allows for importing PO
	605	files from other sources, but also eases the evolution of the current
	606	convention, evolution driven mostly by aesthetic concerns, as of now.
	607	It is easy to make suggested adjustments at a later time, as the
	608	normalizing command and eventually, other GNU <CODE>gettext</CODE> tools
	609	should greatly automate conformance. A description of the canonical
	610	string format is given below, for the particular benefit of those not
	611	having GNU Emacs handy, and who would nevertheless want to handcraft
	612	their PO files in nice ways.
	613
	614	</P>
	615	<P>
	616	Right now, in PO mode, strings are single line or multi-line. A string
	617	goes multi-line if and only if it has <EM>embedded</EM> newlines, that
	618	is, if it matches <SAMP>`[^\n]\n+[^\n]'</SAMP>. So, we would have:
	619
	620	</P>
	621
	622	<PRE>
	623	msgstr "\n\nHello, world!\n\n\n"
	624	</PRE>
	625
	626	<P>
	627	but, replacing the space by a newline, this becomes:
	628
	629	</P>
	630
	631	<PRE>
	632	msgstr ""
	633	"\n"
	634	"\n"
	635	"Hello,\n"
	636	"world!\n"
	637	"\n"
	638	"\n"
	639	</PRE>
	640
	641	<P>
	642	We are deliberately using a caricatural example, here, to make the
	643	point clearer. Usually, multi-lines are not that bad looking.
	644	It is probable that we will implement the following suggestion.
	645	We might lump together all initial newlines into the empty string,
	646	and also all newlines introducing empty lines (that is, for <VAR>n</VAR>
	647	> 1, the <VAR>n</VAR>-1'th last newlines would go together on a separate
	648	string), so making the previous example appear:
	649
	650	</P>
	651
	652	<PRE>
	653	msgstr "\n\n"
	654	"Hello,\n"
	655	"world!\n"
	656	"\n\n"
	657	</PRE>
	658
	659	<P>
	660	There are a few yet undecided little points about string normalization,
	661	to be documented in this manual, once these questions settle.
	662
	663	</P>
	664	<P><HR><P>
	665	<p>Go to the <A HREF="gettext_1.html">first</A>, <A HREF="gettext_1.html">previous</A>, <A HREF="gettext_3.html">next</A>, <A HREF="gettext_12.html">last</A> section, <A HREF="gettext_toc.html">table of contents</A>.
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