Annotation of src/usr.bin/less/prompt.c, Revision 1.8
1.1 etheisen 1: /*
1.7 millert 2: * Copyright (C) 1984-2002 Mark Nudelman
1.1 etheisen 3: *
1.7 millert 4: * You may distribute under the terms of either the GNU General Public
5: * License or the Less License, as specified in the README file.
1.1 etheisen 6: *
1.7 millert 7: * For more information about less, or for information on how to
8: * contact the author, see the README file.
1.1 etheisen 9: */
10:
11:
12: /*
13: * Prompting and other messages.
14: * There are three flavors of prompts, SHORT, MEDIUM and LONG,
15: * selected by the -m/-M options.
16: * There is also the "equals message", printed by the = command.
17: * A prompt is a message composed of various pieces, such as the
18: * name of the file being viewed, the percentage into the file, etc.
19: */
20:
21: #include "less.h"
22: #include "position.h"
23:
24: extern int pr_type;
25: extern int hit_eof;
26: extern int new_file;
27: extern int sc_width;
28: extern int so_s_width, so_e_width;
29: extern int linenums;
1.7 millert 30: extern int hshift;
31: extern int ismore;
1.1 etheisen 32: extern int sc_height;
33: extern int jump_sline;
34: extern IFILE curr_ifile;
35: #if EDITOR
36: extern char *editor;
1.7 millert 37: extern char *editproto;
1.1 etheisen 38: #endif
39:
40: /*
41: * Prototypes for the three flavors of prompts.
42: * These strings are expanded by pr_expand().
43: */
1.7 millert 44: static constant char s_proto[] =
45: "?n?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x..%t";
46: static constant char m_proto[] =
47: "?f%f .?m(%T %i of %m) ..?e(END) ?x- Next\\: %x.:?pB%pB\\%:byte %bB?s/%s...%t";
48: static constant char M_proto[] =
49: "?f%f .?n?m(%T %i of %m) ..?ltlines %lt-%lb?L/%L. :byte %bB?s/%s. .?e(END) ?x- Next\\: %x.:?pB%pB\\%..%t";
50: static constant char more_proto[] =
51: "--More--.?e(END) ?x- Next\\: %x.:(?pB%pB\\%:byte %bB?s/%s..).%t";
52: static constant char e_proto[] =
53: "?f%f .?m(%T %i of %m) .?ltlines %lt-%lb?L/%L. .byte %bB?s/%s. ?e(END) :?pB%pB\\%..%t";
54: static constant char h_proto[] =
55: "HELP -- ?eEND -- Press g to see it again:Press RETURN for more., or q when done";
56: static constant char w_proto[] =
57: "Waiting for data";
1.1 etheisen 58:
59: public char *prproto[3];
1.7 millert 60: public char constant *eqproto = e_proto;
61: public char constant *hproto = h_proto;
62: public char constant *wproto = w_proto;
1.1 etheisen 63:
1.7 millert 64: static char message[PROMPT_SIZE];
1.1 etheisen 65: static char *mp;
66:
67: /*
68: * Initialize the prompt prototype strings.
69: */
70: public void
71: init_prompt()
72: {
1.7 millert 73: prproto[0] = save(ismore ? more_proto : s_proto);
1.1 etheisen 74: prproto[1] = save(m_proto);
75: prproto[2] = save(M_proto);
76: eqproto = save(e_proto);
1.7 millert 77: hproto = save(h_proto);
78: wproto = save(w_proto);
1.1 etheisen 79: }
80:
81: /*
1.7 millert 82: * Append a string to the end of the message.
1.1 etheisen 83: */
84: static void
1.7 millert 85: ap_str(s)
86: char *s;
1.1 etheisen 87: {
1.7 millert 88: int len;
89:
90: len = strlen(s);
91: if (mp + len >= message + PROMPT_SIZE)
92: len = message + PROMPT_SIZE - mp - 1;
93: strncpy(mp, s, len);
94: mp += len;
95: *mp = '\0';
96: }
97:
98: /*
99: * Append a character to the end of the message.
100: */
101: static void
102: ap_char(c)
103: char c;
104: {
105: char buf[2];
106:
107: buf[0] = c;
108: buf[1] = '\0';
109: ap_str(buf);
1.1 etheisen 110: }
111:
112: /*
113: * Append a POSITION (as a decimal integer) to the end of the message.
114: */
115: static void
116: ap_pos(pos)
117: POSITION pos;
118: {
1.7 millert 119: char buf[INT_STRLEN_BOUND(pos) + 2];
120:
121: postoa(pos, buf, sizeof(buf));
122: ap_str(buf);
1.1 etheisen 123: }
124:
125: /*
1.7 millert 126: * Append a line number to the end of the message.
1.1 etheisen 127: */
1.7 millert 128: static void
129: ap_linenum(linenum)
130: LINENUM linenum;
1.1 etheisen 131: {
1.7 millert 132: char buf[INT_STRLEN_BOUND(linenum) + 2];
133:
134: linenumtoa(linenum, buf, sizeof(buf));
135: ap_str(buf);
1.1 etheisen 136: }
137:
138: /*
1.7 millert 139: * Append an integer to the end of the message.
1.1 etheisen 140: */
141: static void
1.7 millert 142: ap_int(num)
143: int num;
1.1 etheisen 144: {
1.7 millert 145: char buf[INT_STRLEN_BOUND(num) + 2];
146:
147: inttoa(num, buf, sizeof(buf));
148: ap_str(buf);
1.1 etheisen 149: }
150:
151: /*
152: * Append a question mark to the end of the message.
153: */
154: static void
155: ap_quest()
156: {
1.7 millert 157: ap_str("?");
1.1 etheisen 158: }
159:
160: /*
161: * Return the "current" byte offset in the file.
162: */
163: static POSITION
164: curr_byte(where)
165: int where;
166: {
167: POSITION pos;
168:
169: pos = position(where);
170: while (pos == NULL_POSITION && where >= 0 && where < sc_height)
171: pos = position(++where);
172: if (pos == NULL_POSITION)
173: pos = ch_length();
174: return (pos);
175: }
176:
177: /*
178: * Return the value of a prototype conditional.
179: * A prototype string may include conditionals which consist of a
180: * question mark followed by a single letter.
181: * Here we decode that letter and return the appropriate boolean value.
182: */
183: static int
184: cond(c, where)
185: char c;
186: int where;
187: {
1.7 millert 188: POSITION len;
189:
1.1 etheisen 190: switch (c)
191: {
192: case 'a': /* Anything in the message yet? */
193: return (mp > message);
194: case 'b': /* Current byte offset known? */
195: return (curr_byte(where) != NULL_POSITION);
1.7 millert 196: case 'c':
197: return (hshift != 0);
1.1 etheisen 198: case 'e': /* At end of file? */
199: return (hit_eof);
200: case 'f': /* Filename known? */
201: return (strcmp(get_filename(curr_ifile), "-") != 0);
202: case 'l': /* Line number known? */
1.7 millert 203: case 'd': /* Same as l */
1.1 etheisen 204: return (linenums);
205: case 'L': /* Final line number known? */
1.7 millert 206: case 'D': /* Same as L */
1.1 etheisen 207: return (linenums && ch_length() != NULL_POSITION);
208: case 'm': /* More than one file? */
1.7 millert 209: #if TAGS
210: return (ntags() ? (ntags() > 1) : (nifile() > 1));
211: #else
1.1 etheisen 212: return (nifile() > 1);
1.7 millert 213: #endif
1.1 etheisen 214: case 'n': /* First prompt in a new file? */
1.7 millert 215: #if TAGS
216: return (ntags() ? 1 : new_file);
217: #else
1.1 etheisen 218: return (new_file);
1.7 millert 219: #endif
220: case 'p': /* Percent into file (bytes) known? */
1.1 etheisen 221: return (curr_byte(where) != NULL_POSITION &&
222: ch_length() > 0);
1.7 millert 223: case 'P': /* Percent into file (lines) known? */
224: return (currline(where) != 0 &&
225: (len = ch_length()) > 0 &&
226: find_linenum(len) != 0);
1.1 etheisen 227: case 's': /* Size of file known? */
228: case 'B':
229: return (ch_length() != NULL_POSITION);
230: case 'x': /* Is there a "next" file? */
1.7 millert 231: #if TAGS
232: if (ntags())
233: return (0);
234: #endif
1.1 etheisen 235: return (next_ifile(curr_ifile) != NULL_IFILE);
236: }
237: return (0);
238: }
239:
240: /*
241: * Decode a "percent" prototype character.
242: * A prototype string may include various "percent" escapes;
243: * that is, a percent sign followed by a single letter.
244: * Here we decode that letter and take the appropriate action,
245: * usually by appending something to the message being built.
246: */
247: static void
1.7 millert 248: protochar(c, where, iseditproto)
1.1 etheisen 249: int c;
250: int where;
1.7 millert 251: int iseditproto;
1.1 etheisen 252: {
253: POSITION pos;
254: POSITION len;
255: int n;
1.7 millert 256: LINENUM linenum;
257: LINENUM last_linenum;
1.1 etheisen 258: IFILE h;
259:
260: switch (c)
261: {
262: case 'b': /* Current byte offset */
263: pos = curr_byte(where);
264: if (pos != NULL_POSITION)
265: ap_pos(pos);
266: else
267: ap_quest();
268: break;
1.7 millert 269: case 'c':
270: ap_int(hshift);
271: break;
272: case 'd': /* Current page number */
273: linenum = currline(where);
274: if (linenum > 0 && sc_height > 1)
275: ap_linenum(((linenum - 1) / (sc_height - 1)) + 1);
276: else
277: ap_quest();
278: break;
279: case 'D': /* Last page number */
280: len = ch_length();
281: if (len == NULL_POSITION || len == ch_zero() ||
282: (linenum = find_linenum(len)) <= 0)
283: ap_quest();
284: else
285: ap_linenum(((linenum - 1) / (sc_height - 1)) + 1);
286: break;
1.1 etheisen 287: #if EDITOR
288: case 'E': /* Editor name */
289: ap_str(editor);
290: break;
291: #endif
292: case 'f': /* File name */
293: ap_str(get_filename(curr_ifile));
294: break;
295: case 'i': /* Index into list of files */
1.7 millert 296: #if TAGS
297: if (ntags())
298: ap_int(curr_tag());
299: else
300: #endif
301: ap_int(get_index(curr_ifile));
1.1 etheisen 302: break;
303: case 'l': /* Current line number */
1.7 millert 304: linenum = currline(where);
305: if (linenum != 0)
306: ap_linenum(linenum);
1.1 etheisen 307: else
308: ap_quest();
309: break;
310: case 'L': /* Final line number */
311: len = ch_length();
312: if (len == NULL_POSITION || len == ch_zero() ||
1.7 millert 313: (linenum = find_linenum(len)) <= 0)
1.1 etheisen 314: ap_quest();
315: else
1.7 millert 316: ap_linenum(linenum-1);
1.1 etheisen 317: break;
318: case 'm': /* Number of files */
1.7 millert 319: #if TAGS
320: n = ntags();
321: if (n)
322: ap_int(n);
323: else
324: #endif
325: ap_int(nifile());
1.1 etheisen 326: break;
1.7 millert 327: case 'p': /* Percent into file (bytes) */
1.1 etheisen 328: pos = curr_byte(where);
329: len = ch_length();
330: if (pos != NULL_POSITION && len > 0)
331: ap_int(percentage(pos,len));
332: else
333: ap_quest();
334: break;
1.7 millert 335: case 'P': /* Percent into file (lines) */
336: linenum = currline(where);
337: if (linenum == 0 ||
338: (len = ch_length()) == NULL_POSITION || len == ch_zero() ||
339: (last_linenum = find_linenum(len)) <= 0)
340: ap_quest();
341: else
342: ap_int(percentage(linenum, last_linenum));
343: break;
1.1 etheisen 344: case 's': /* Size of file */
345: case 'B':
346: len = ch_length();
347: if (len != NULL_POSITION)
348: ap_pos(len);
349: else
350: ap_quest();
351: break;
352: case 't': /* Truncate trailing spaces in the message */
353: while (mp > message && mp[-1] == ' ')
354: mp--;
355: break;
1.7 millert 356: case 'T': /* Type of list */
357: #if TAGS
358: if (ntags())
359: ap_str("tag");
360: else
361: #endif
362: ap_str("file");
363: break;
1.1 etheisen 364: case 'x': /* Name of next file */
365: h = next_ifile(curr_ifile);
366: if (h != NULL_IFILE)
367: ap_str(get_filename(h));
368: else
369: ap_quest();
370: break;
371: }
372: }
373:
374: /*
375: * Skip a false conditional.
376: * When a false condition is found (either a false IF or the ELSE part
377: * of a true IF), this routine scans the prototype string to decide
378: * where to resume parsing the string.
379: * We must keep track of nested IFs and skip them properly.
380: */
381: static char *
382: skipcond(p)
1.7 millert 383: register char *p;
1.1 etheisen 384: {
1.7 millert 385: register int iflevel;
1.1 etheisen 386:
387: /*
388: * We came in here after processing a ? or :,
389: * so we start nested one level deep.
390: */
391: iflevel = 1;
392:
393: for (;;) switch (*++p)
394: {
395: case '?':
396: /*
397: * Start of a nested IF.
398: */
399: iflevel++;
400: break;
401: case ':':
402: /*
403: * Else.
404: * If this matches the IF we came in here with,
405: * then we're done.
406: */
407: if (iflevel == 1)
408: return (p);
409: break;
410: case '.':
411: /*
412: * Endif.
413: * If this matches the IF we came in here with,
414: * then we're done.
415: */
416: if (--iflevel == 0)
417: return (p);
418: break;
419: case '\\':
420: /*
421: * Backslash escapes the next character.
422: */
423: ++p;
424: break;
425: case '\0':
426: /*
427: * Whoops. Hit end of string.
428: * This is a malformed conditional, but just treat it
429: * as if all active conditionals ends here.
430: */
431: return (p-1);
432: }
433: /*NOTREACHED*/
434: }
435:
1.7 millert 436: /*
437: * Decode a char that represents a position on the screen.
438: */
1.1 etheisen 439: static char *
440: wherechar(p, wp)
441: char *p;
442: int *wp;
443: {
444: switch (*p)
445: {
1.7 millert 446: case 'b': case 'd': case 'l': case 'p': case 'P':
1.1 etheisen 447: switch (*++p)
448: {
449: case 't': *wp = TOP; break;
450: case 'm': *wp = MIDDLE; break;
451: case 'b': *wp = BOTTOM; break;
452: case 'B': *wp = BOTTOM_PLUS_ONE; break;
453: case 'j': *wp = adjsline(jump_sline); break;
454: default: *wp = TOP; p--; break;
455: }
456: }
457: return (p);
458: }
459:
460: /*
461: * Construct a message based on a prototype string.
462: */
463: public char *
464: pr_expand(proto, maxwidth)
465: char *proto;
466: int maxwidth;
467: {
1.7 millert 468: register char *p;
469: register int c;
1.1 etheisen 470: int where;
471:
472: mp = message;
473:
474: if (*proto == '\0')
475: return ("");
476:
477: for (p = proto; *p != '\0'; p++)
478: {
479: switch (*p)
480: {
481: default: /* Just put the character in the message */
1.7 millert 482: ap_char(*p);
1.1 etheisen 483: break;
484: case '\\': /* Backslash escapes the next character */
485: p++;
1.7 millert 486: ap_char(*p);
1.1 etheisen 487: break;
488: case '?': /* Conditional (IF) */
489: if ((c = *++p) == '\0')
490: --p;
491: else
492: {
1.7 millert 493: where = 0;
1.1 etheisen 494: p = wherechar(p, &where);
495: if (!cond(c, where))
496: p = skipcond(p);
497: }
498: break;
499: case ':': /* ELSE */
500: p = skipcond(p);
501: break;
502: case '.': /* ENDIF */
503: break;
504: case '%': /* Percent escape */
505: if ((c = *++p) == '\0')
506: --p;
507: else
508: {
1.7 millert 509: where = 0;
1.1 etheisen 510: p = wherechar(p, &where);
1.7 millert 511: protochar(c, where,
512: #if EDITOR
513: (proto == editproto));
514: #else
515: 0);
516: #endif
517:
1.1 etheisen 518: }
519: break;
520: }
521: }
522:
523: if (mp == message)
524: return (NULL);
525: if (maxwidth > 0 && mp >= message + maxwidth)
526: {
527: /*
528: * Message is too long.
529: * Return just the final portion of it.
530: */
531: return (mp - maxwidth);
532: }
533: return (message);
534: }
535:
536: /*
537: * Return a message suitable for printing by the "=" command.
538: */
539: public char *
540: eq_message()
541: {
542: return (pr_expand(eqproto, 0));
543: }
544:
545: /*
546: * Return a prompt.
547: * This depends on the prompt type (SHORT, MEDIUM, LONG), etc.
548: * If we can't come up with an appropriate prompt, return NULL
549: * and the caller will prompt with a colon.
550: */
551: public char *
552: pr_string()
553: {
1.7 millert 554: char *prompt;
555:
1.8 ! millert 556: prompt = pr_expand(prproto[pr_type], sc_width-so_s_width-so_e_width-2);
1.7 millert 557: new_file = 0;
558: return (prompt);
559: }
560:
561: /*
562: * Return a message suitable for printing while waiting in the F command.
563: */
564: public char *
565: wait_message()
566: {
567: return (pr_expand(wproto, sc_width-so_s_width-so_e_width-2));
1.1 etheisen 568: }