xref: /freebsd/lib/libdpv/dpv.3 (revision 41059135ce931c0f1014a999ffabc6bc470ce856)
1.\" Copyright (c) 2013-2016 Devin Teske
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25.\" $FreeBSD$
26.\"
27.Dd Jan 26, 2016
28.Dt DPV 3
29.Os
30.Sh NAME
31.Nm dpv
32.Nd dialog progress view library
33.Sh LIBRARY
34.Lb libdpv
35.Sh SYNOPSIS
36.In dpv.h
37.Ft int
38.Fo dpv
39.Fa "struct dpv_config *config, struct dpv_file_node *file_list"
40.Fc
41.Ft void
42.Fo dpv_free
43.Fa "void"
44.Fc
45.Sh DESCRIPTION
46The
47.Nm
48library provides an interface for creating complex
49.Dq gauge
50widgets for displaying progress on various actions.
51The
52.Nm
53library can display progress with one of
54.Xr dialog 3 ,
55.Xr dialog 1 ,
56or
57.Xr Xdialog 1
58.Pq x11/xdialog from the ports tree .
59.Pp
60The
61.Fn dpv
62.Fa config
63argument contains the following properties for configuring global display
64features:
65.Bd -literal -offset indent
66struct dpv_config {
67    uint8_t          keep_tite;     /* Cleaner exit for scripts */
68    enum dpv_display display_type;  /* Def. DPV_DISPLAY_LIBDIALOG */
69    enum dpv_output  output_type;   /* Default DPV_OUTPUT_NONE */
70    int              debug;         /* Enable debug on stderr */
71    int              display_limit; /* Files/page. Default -1 */
72    int              label_size;    /* Label size. Default 28 */
73    int              pbar_size;     /* Mini-progress size */
74    int              dialog_updates_per_second; /* Default 16 */
75    int              status_updates_per_second; /* Default 2 */
76    uint16_t         options;       /* Default 0 (none) */
77    char             *title;        /* Widget title */
78    char             *backtitle;    /* Widget backtitle */
79    char             *aprompt;      /* Append. Default NULL */
80    char             *pprompt;      /* Prefix. Default NULL */
81    char             *msg_done;     /* Default `Done' */
82    char             *msg_fail;     /* Default `Fail' */
83    char             *msg_pending;  /* Default `Pending' */
84    char             *output;       /* Output format string */
85    const char       *status_solo;  /* dialog(3) solo-status format.
86                                     * Default DPV_STATUS_SOLO */
87    const char       *status_many;  /* dialog(3) many-status format.
88                                     * Default DPV_STATUS_MANY */
89
90    /*
91     * Function pointer; action to perform data transfer
92     */
93    int (*action)(struct dpv_file_node *file, int out);
94};
95
96enum dpv_display {
97    DPV_DISPLAY_LIBDIALOG = 0, /* Use dialog(3) (default) */
98    DPV_DISPLAY_STDOUT,        /* Use stdout */
99    DPV_DISPLAY_DIALOG,        /* Use spawned dialog(1) */
100    DPV_DISPLAY_XDIALOG,       /* Use spawned Xdialog(1) */
101};
102
103enum dpv_output {
104    DPV_OUTPUT_NONE = 0, /* No output (default) */
105    DPV_OUTPUT_FILE,     /* Read `output' member as file path */
106    DPV_OUTPUT_SHELL,    /* Read `output' member as shell cmd */
107};
108.Ed
109.Pp
110The
111.Va options
112member of the
113.Fn dpv
114.Fa config
115argument is a mask of bit fields indicating various processing options.
116Possible flags are as follows:
117.Bl -tag -width DPV_NO_OVERRUN
118.It Dv DPV_TEST_MODE
119Enable test mode.
120In test mode, the
121.Fn action
122callback of the
123.Fa config
124argument is not called but instead simulated-data is used to drive progress.
125Appends
126.Dq [TEST MODE]
127to the status line
128.Po
129to override, set the
130.Va status_format
131member of the
132.Fn dpv
133.Fa config
134argument;
135e.g., to
136.Dv DPV_STATUS_DEFAULT
137.Pc .
138.It Dv DPV_WIDE_MODE
139Enable wide mode.
140In wide mode, the length of the
141.Va aprompt
142and
143.Va pprompt
144members of the
145.Fn dpv
146.Fa config
147argument will bump the width of the gauge widget.
148Prompts wider than the maximum width will wrap
149.Po
150unless using
151.Xr Xdialog 1 ;
152see BUGS section below
153.Pc .
154.It Dv DPV_NO_LABELS
155Disables the display of labels associated with each transfer
156.Po
157.Va label_size
158member of
159.Fn dpv
160.Fa config
161argument is ignored
162.Pc .
163.It Dv DPV_USE_COLOR
164Force the use of color even if the
165.Va display_type
166does not support color
167.Po
168.Ev USE_COLOR
169environment variable is ignored
170.Pc .
171.It Dv DPV_NO_OVERRUN
172When enabled, callbacks for the current
173.Vt dpv_file_node
174are terminated when
175.Fn action
176returns 100 or greater
177.Po
178alleviates the need to change the
179.Va status
180of the current
181.Vt dpv_file_node
182but may also cause file truncation if the stream exceeds expected length
183.Pc .
184.El
185.Pp
186The
187.Fa file_list
188argument to
189.Fn dpv
190is a pointer to a
191.Dq linked-list ,
192described as follows in
193.In dpv.h :
194.Bd -literal -offset indent
195struct dpv_file_node {
196    enum dpv_status    status; /* status of read operation */
197    char               *msg;   /* display instead of "Done/Fail" */
198    char               *name;  /* name of file to read */
199    char               *path;  /* path to file */
200    long long          length; /* expected size */
201    long long          read;   /* number units read (e.g., bytes) */
202    struct dpv_file_node *next;/* pointer to next (end with NULL) */
203};
204.Ed
205.Pp
206For each of the items in the
207.Fa file_list
208.Dq linked-list
209argument, the
210.Fn action
211callback member of the
212.Fn dpv
213.Fa config
214argument is called.
215The
216.Fn action
217function should perform a
218.Dq nominal
219action on the file and return.
220The return value of
221.Vt int
222represents the current progress percentage
223.Pq 0-100
224for the current file.
225.Pp
226The
227.Fn action
228callback provides two variables for each call.
229.Fa file
230provides a reference to the current
231.Vt dpv_file_node
232being processed.
233.Fa out
234provides a file descriptor where the data should go.
235.Pp
236If the
237.Va output
238member of the
239.Fn dpv
240.Fa config
241argument was set to DPV_OUTPUT_NONE
242.Pq default ; when invoking Fn dpv ,
243the
244.Fa out
245file descriptor of
246.Fn action
247will be zero and should be ignored.
248If
249.Fa output
250was set to DPV_OUTPUT_FILE,
251.Fa out
252will be an open file descriptor to a file.
253If
254.Fa output
255was set to DPV_OUTPUT_SHELL,
256.Fa out
257will be an open file descriptor to a pipe for a spawned shell program.
258When
259.Fa out
260is greater than zero, you should write any data you have read back to
261.Fa out .
262.Pp
263To abort
264.Fn dpv ,
265either from the
266.Fn action
267callback or asynchronously from a signal handler, two globals are provided via
268.In dpv.h :
269.Bd -literal -offset indent
270extern int dpv_interrupt; /* Set to TRUE in interrupt handler */
271extern int dpv_abort;     /* Set to true in callback to abort */
272.Ed
273.Pp
274These globals are not automatically reset and must be manually maintained.
275Don't forget to reset these globals before subsequent invocations of
276.Fn dpv
277when making multiple calls from the same program.
278.Pp
279In addition, the
280.Va status
281member of the
282.Fn action
283.Fa file
284argument can be used to control callbacks for the current file.
285The
286.Va status
287member can be set to any of the following from
288.In dpv.h :
289.Bd -literal -offset indent
290enum dpv_status {
291	DPV_STATUS_RUNNING = 0, /* Running (default) */
292	DPV_STATUS_DONE,        /* Completed */
293	DPV_STATUS_FAILED,      /* Oops, something went wrong */
294};
295.Ed
296.Pp
297The default
298.Fa status
299is zero, DPV_STATUS_RUNING, which keeps the callbacks coming for the current
300.Fn file .
301Setting
302.Ql file->status
303to anything other than DPV_STATUS_RUNNING will cause
304.Fn dpv
305to loop to the next file, effecting the next callback, if any.
306.Pp
307The
308.Fn action
309callback is responsible for calculating percentages and
310.Pq recommended
311maintaining a
312.Nm
313global counter so
314.Fn dpv
315can display throughput statistics.
316Percentages are reported through the
317.Vt int
318return value of the
319.Fn action
320callback.
321Throughput statistics are calculated from the following global
322.Vt int
323in
324.In dpv.h :
325.Bd -literal -offset indent
326extern int dpv_overall_read;
327.Ed
328.Pp
329This should be set to the number of bytes that have been read for all files.
330Throughput information is displayed in the status line
331.Pq only available when using Xr dialog 3
332at the bottom of the screen.
333See DPV_DISPLAY_LIBDIALOG above.
334.Pp
335Note that
336.Va dpv_overall_read
337does not have to represent bytes.
338For example, you can change the
339.Va status_format
340to display something other than
341.Dq Li bytes
342and increment
343.Va dpv_overall_read
344accordingly
345.Pq e.g., counting lines .
346.Pp
347When
348.Fn dpv
349is processing the current file, the
350.Va length
351and
352.Va read
353members of the
354.Fn action
355.Fa file
356argument are used for calculating the display of mini progress bars
357.Po
358if enabled; see
359.Va pbar_size
360above
361.Pc .
362If the
363.Va length
364member of the current
365.Fa file
366is less than zero
367.Pq indicating an unknown file length ,
368a
369.Xr humanize_number 3
370version of the
371.Va read
372member is used instead of a traditional progress bar.
373Otherwise a progress bar is calculated as percentage read to file length.
374.Fn action
375callback must maintain these member values for mini-progress bars.
376.Pp
377The
378.Fn dpv_free
379function performs
380.Xr free 3
381on private global variables initialized by
382.Fn dpv .
383.Sh ENVIRONMENT
384The following environment variables are referenced by
385.Nm :
386.Bl -tag -width ".Ev USE_COLOR"
387.It Ev DIALOG
388Override command string used to launch
389.Xr dialog 1
390.Pq requires Dv DPV_DISPLAY_DIALOG
391or
392.Xr Xdialog 1
393.Pq requires Dv DPV_DISPLAY_XDIALOG ;
394default is either
395.Ql dialog
396.Pq for Dv DPV_DISPLAY_DIALOG
397or
398.Ql Xdialog
399.Pq for Dv DPV_DISPLAY_XDIALOG .
400.It Ev DIALOGRC
401If set and non-NULL, path to
402.Ql .dialogrc
403file.
404.It Ev HOME
405If
406.Ql Ev $DIALOGRC
407is either not set or NULL, used as a prefix to
408.Ql .dialogrc
409.Pq i.e., Ql $HOME/.dialogrc .
410.It Ev USE_COLOR
411If set and NULL, disables the use of color when using
412.Xr dialog 1
413.Pq does not apply to Xr Xdialog 1 .
414.It Ev msg_done Ev msg_fail Ev msg_pending
415Internationalization strings for overriding the default English strings
416.Ql Done ,
417.Ql Fail ,
418and
419.Ql Pending
420respectively.
421To prevent their usage, explicitly set the
422.Va msg_done ,
423.Va msg_fail ,
424and
425.Va msg_pending
426members of
427.Fn dpv
428.Fa config
429argument to default macros
430.Pq DPV_DONE_DEFAULT, DPV_FAIL_DEFAULT, and DPV_PENDING_DEFAULT
431or desired values.
432.El
433.Sh FILES
434.Bl -tag -width ".Pa $HOME/.dialogrc" -compact
435.It Pa $HOME/.dialogrc
436.El
437.Sh SEE ALSO
438.Xr dialog 1 ,
439.Xr Xdialog 1 ,
440.Xr dialog 3
441.Sh HISTORY
442The
443.Nm
444library first appeared in
445.Fx 10.2 .
446.Sh AUTHORS
447.An Devin Teske Aq dteske@FreeBSD.org
448.Sh BUGS
449.Xr Xdialog 1 ,
450when given both
451.Ql Fl -title Ar title
452.Po
453see above
454.Ql Va title
455member of
456.Va struct dpv_config
457.Pc
458and
459.Ql Fl -backtitle Ar backtitle
460.Po
461see above
462.Ql Va backtitle
463member of
464.Va struct dpv_config
465.Pc ,
466displays the backtitle in place of the title and vice-versa.
467.Pp
468.Xr Xdialog 1
469does not wrap long prompt texts received after initial launch.
470This is a known issue with the
471.Ql --gauge
472widget in
473.Xr Xdialog 1 .
474Embed escaped newlines within prompt text(s) to force line breaks.
475.Pp
476.Xr dialog 1
477does not display the first character after a series of escaped escape-sequences
478(e.g., ``\\\\n'' produces ``\\'' instead of ``\\n'').
479This is a known issue with
480.Xr dialog 1
481and does not affect
482.Xr dialog 3
483or
484.Xr Xdialog 1 .
485.Pp
486If your application ignores
487.Ev USE_COLOR
488when set and NULL before calling
489.Xr dpv 3
490with color escape sequences anyway,
491.Xr dialog 3
492and
493.Xr dialog 1
494may not render properly.
495Workaround is to detect when
496.Ev USE_COLOR
497is set and NULL and either not use color escape sequences at that time or use
498.Xr unsetenv 3
499to unset
500.Ev USE_COLOR ,
501forcing interpretation of color sequences.
502This does not effect
503.Xr Xdialog 1 ,
504which renders the color escape sequences as plain text.
505See
506.Do
507embedded "\\Z" sequences
508.Dc
509in
510.Xr dialog 1
511for additional information.
512