summaryrefslogtreecommitdiff
path: root/libps/fmt.c
blob: 72985ca43bddf937cc062026fb57d5ec8176b231 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
/* Implements the ps_fmt type, which describes how to output a user-readable
   version of a proc_stat.

   Copyright (C) 1995, 1996 Free Software Foundation, Inc.

   Written by Miles Bader <miles@gnu.ai.mit.edu>

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <ctype.h>

#include "ps.h"
#include "common.h"

/* ---------------------------------------------------------------- */

/* An internal version of ps_fmt_create that also returns a string describing
   why EINVAL was returned.  */
static error_t
_fmt_create (char *src, struct ps_fmt_specs *fmt_specs, struct ps_fmt **fmt,
	     char **err_string)
{
  struct ps_fmt *new_fmt;
  int needs = 0;
  int fields_alloced = 10;
  struct ps_fmt_field *fields = NEWVEC (struct ps_fmt_field, fields_alloced);
  struct ps_fmt_field *field = fields; /* current last field */

  if (fields == NULL)
    return ENOMEM;

  new_fmt = NEW (struct ps_fmt);
  if (fmt == NULL)
    {
      FREE (fields);
      return ENOMEM;
    }

  /* Make a private copy of SRC so we can mutate it.  */
  new_fmt->src = NEWVEC (char, strlen (src) + 1);
  if (new_fmt->src == NULL)
    {
      FREE (fields);
      FREE (new_fmt);
      return ENOMEM;
    }
  strcpy (new_fmt->src, src);
  src = new_fmt->src;

  while (*src != '\0')
    {
      if (field - fields == fields_alloced)
	/* Time to grow FIELDS to make room for more.  */
	{
	  int offs = field - fields;

	  fields_alloced += 10;
	  fields = GROWVEC (fields, struct ps_fmt_field, fields_alloced);

	  if (fields == NULL)
	    {
	      FREE (new_fmt);
	      FREE (new_fmt->src);
	      return ENOMEM;
	    }

	  field = fields + offs;
	}

      /* Find the text to be reproduced verbatim between the last field and
	 the next one; we'll add this a prefix to FIELD.  */
      field->pfx = src;
      while (*src != '\0' && *src != '~')
	src++;
      field->pfx_len = src - field->pfx;

      field->spec = NULL;
      field->title = NULL;
      field->width = 0;

      if (*src != '\0')
	/* Another format-spec.  */
	{
	  char *name;
	  int sign = 1;
	  int explicit_width = FALSE; /* True if the width set from SRC.  */
	  char *spec_start = src++;

	  /* Read an explicit field width.  */
	  field->width = 0;
	  if (*src == '-')
	    sign = -1, src++;
	  while (isdigit (*src))
	    {
	      field->width = field->width * 10 + (*src++ - '0');
	      explicit_width = TRUE;
	    }

	  /* Skip `/' between optional width and spec name.  */
	  if (*src == '/')
	    src++;

	  /* The name of the spec, or `TITLE=NAME'.  */
	  name = src;
	  while (*src != '\0' && !isspace (*src) && *src != '/' && *src != '=')
	    src++;

	  if (*src == '=')
	    /* A title different from the spec name; the actual name follows
	       the `='.  */
	    {
	      field->title = name;
	      *src++ = '\0';

	      /* Now read the real name.  */
	      name = src;
	      while (*src != '\0' && !isspace (*src) && *src != '/')
		src++;
	    }

	  /* Now that we've parsed everything in this spec, move the whole
	     thing down one byte (trashing the leading `~') so that we have
	     room to NUL-terminate the name for which we're searching.  We
	     also adjust any pointers into this spec-string accordingly.  */
	  bcopy (spec_start + 1, spec_start, src - spec_start - 1);
	  name--;
	  if (field->title)
	    field->title--;

	  /* Now that we've made room, do the termination of NAME.  */
	  src[-1] = '\0';

	  field->spec = ps_fmt_specs_find (fmt_specs, name);
	  if (! field->spec)
	    /* Failed to find any named spec called NAME.  */
	    {
	      if (err_string)
		asprintf (err_string, "%s: Unknown format spec", name);

	      FREE (new_fmt->src);
	      FREE (fields);
	      FREE (new_fmt);

	      return EINVAL;
	    }

	  if (! field->title)
	    /* No explicit title specified in the fmt string.  */
	    if (field->spec->title)
	      field->title = field->spec->title; /* But the spec has one.  */
	    else
	      field->title = name; /* Just use the field name.  */

	  /* Add FIELD's required pstat_flags to FMT's set */
	  needs |= ps_getter_needs (ps_fmt_spec_getter (field->spec));

	  if (!explicit_width)
	    field->width = ps_fmt_spec_width (field->spec);

	  /* Skip optional trailing `/' after the spec name.  */
	  if (*src == '/')
	    src++;

	  /* Remember the width's sign (we put it here after possibly using a
	     default width so that the user may include a `-' with no width
	     to flip the justification of the default width).  */
	  field->width *= sign;

	  {
	    /* Force the field to be wide enough to hold the title.  */
	    int width = field->width;
	    int tlen = strlen (field->title);
	    if (width != 0 && tlen > ABS (width))
	      field->width = (width > 0 ? tlen : -tlen);
	  }
	}

      field++;
    }

  new_fmt->fields = fields;
  new_fmt->num_fields = field - fields;
  new_fmt->needs = needs;
  new_fmt->inval = 0;

  *fmt = new_fmt;

  return 0;
}

/* Make a PS_FMT_T by parsing the string SRC, searching for any named
   field specs in FMT_SPECS, and returning the result in FMT.  If a memory
   allocation error occurs, ENOMEM is returned.  If SRC contains an unknown
   field name, EINVAL is returned.  Otherwise 0 is returned.  See ps.h for an
   explanation of how FMT is derived from SRC.  */
error_t
ps_fmt_create (char *src, struct ps_fmt_specs *fmt_specs, struct ps_fmt **fmt)
{
  return _fmt_create (src, fmt_specs, fmt, 0);
}

/* Given the same arguments as a previous call to ps_fmt_create that returned
   an error, this function returns a malloced string describing the error.  */
void
ps_fmt_creation_error (char *src, struct ps_fmt_specs *fmt_specs, char **error)
{
  struct ps_fmt *fmt;
  error_t err = _fmt_create (src, fmt_specs, &fmt, error);
  if (err != EINVAL)		/* ? */
    asprintf (error, "%s", strerror (err));
  if (! err)
    ps_fmt_free (fmt);
}

/* Free FMT, and any resources it consumes.  */
void 
ps_fmt_free (struct ps_fmt *fmt)
{
  FREE (fmt->src);
  FREE (fmt->fields);
  FREE (fmt);
}

/* ---------------------------------------------------------------- */

/* Write an appropiate header line for FMT, containing the titles of all its
   fields appropiately aligned with where the values would be printed, to
   STREAM (without a trailing newline).  If count is non-NULL, the total
   number number of characters output is added to the integer it points to.
   If any fatal error occurs, the error code is returned, otherwise 0.  */
error_t
ps_fmt_write_titles (struct ps_fmt *fmt, struct ps_stream *stream)
{
  error_t err = 0;
  struct ps_fmt_field *field = ps_fmt_fields (fmt);
  int left = ps_fmt_num_fields (fmt);

  while (left-- > 0 && !err)
    {
      const char *pfx = ps_fmt_field_prefix (field);
      int pfx_len = ps_fmt_field_prefix_length (field);

      if (pfx_len > 0)
	err = ps_stream_write (stream, pfx, pfx_len);

      if (ps_fmt_field_fmt_spec (field) != NULL && !err)
	{
	  const char *title = ps_fmt_field_title (field);
	  int width = ps_fmt_field_width (field);

	  if (title == NULL)
	    title = "??";

	  err = ps_stream_write_field (stream, title, width);
	}

      field++;
    }

  return err;
}

/* Format a description as instructed by FMT, of the process described by PS
   to STREAM (without a trailing newline).  If count is non-NULL, the total
   number number of characters output is added to the integer it points to.
   If any fatal error occurs, the error code is returned, otherwise 0.  */
error_t
ps_fmt_write_proc_stat (struct ps_fmt *fmt, struct proc_stat *ps, struct ps_stream *stream)
{
  error_t err = 0;
  struct ps_fmt_field *field = ps_fmt_fields (fmt);
  int nfields = ps_fmt_num_fields (fmt);
  int have = proc_stat_flags (ps);

  while (nfields-- > 0 && !err)
    {
      const struct ps_fmt_spec *spec = ps_fmt_field_fmt_spec (field);
      const char *pfx = ps_fmt_field_prefix (field);
      int pfx_len = ps_fmt_field_prefix_length (field);

      if (pfx_len > 0)
	err = ps_stream_write (stream, pfx, pfx_len);

      if (spec != NULL && !err)
	{
	  int need = ps_getter_needs (ps_fmt_spec_getter (spec));
	  int width = ps_fmt_field_width (field);

	  /* do we have the resources to print this field? */
	  if ((need & have) == need)
	    /* Yup */
	    {
	      int (*output_fn)() = (int (*)())ps_fmt_spec_output_fn (spec);
	      const struct ps_getter *getter = ps_fmt_spec_getter (spec);
	      err = output_fn (ps, getter, width, stream);
	    }
	  else
	    /* Something to display in invalid fields.  */
	    err = ps_stream_write_field (stream, fmt->inval ?: "", width);
	}

      field++;
    }

  return err;
}

/* ---------------------------------------------------------------- */

/* Remove those fields from FMT for which the function FN, when called on the
   field's format spec, returns true.  Appropiate inter-field characters are
   also removed: those *following* deleted fields at the beginning of the
   fmt, and those *preceeding* deleted fields *not* at the beginning. */
void
ps_fmt_squash (struct ps_fmt *fmt, int (*fn)(const struct ps_fmt_spec *spec))
{
  int nfields = fmt->num_fields;
  struct ps_fmt_field *fields = fmt->fields, *field = fields;
  /* As we're removing some fields, we must recalculate the set of ps flags
     needed by all fields.  */
  ps_flags_t need = 0;

  while ((field - fields) < nfields)
    {
      const struct ps_fmt_spec *spec = field->spec;

      if (spec != NULL && (*fn)(spec))
	/* Squash this field! */
	{
	  /* Save the old prefix, in case we're deleting the first field,
	     and need to prepend it to the next field.  */
	  const char *beg_pfx = field->pfx; 
	  int beg_pfx_len = field->pfx_len;

	  nfields--;

	  /* Shift down all following fields over this one.  */
	  if (nfields > 0)
	    bcopy (field + 1, field,
		  (nfields - (field - fields)) * sizeof *field);

	  if (field == fields)
	    /* This is the first field, so move its prefix to the
	       following field (overwriting that field's prefix).  This
	       is to ensure that the beginning of the format string is
	       preserved in preference to the middle, as it is more
	       likely to be significant.  */
	    {
	      if (nfields == 0)
		/* no following fields, so just make a new end field (we're
		   sure to have room, as we just vacated a space).  */
		{
		  nfields++;
		  field->pfx = beg_pfx;
		  field->pfx_len = beg_pfx_len;
		  field->spec = NULL;
		}
	      else if (field->spec == NULL)
		/* One following field with only a prefix -- the suffix
		   of the format string.  Tack the prefix on before the
		   suffix so we preserve both the beginning and the end
		   of the format string.  We know there's space in our
		   copy of the source string, because we've just squashed
		   a field which took at least that much room (as it
		   previously contained the same prefix).  */
		{
		  field->pfx -= beg_pfx_len;
		  field->pfx_len += beg_pfx_len;
		  bcopy (beg_pfx, (char *)field->pfx, beg_pfx_len);
		}
	      else
		/* otherwise just replace the next field's prefix with
		   the beginning one */
		{
		  field->pfx = beg_pfx;
		  field->pfx_len = beg_pfx_len;
		}
	    }
	}
      else
	/* don't squash this field, just move to the next one */
	{
	  need |= ps_getter_needs (ps_fmt_spec_getter (spec));
	  field++;
	}
    }

  fmt->num_fields = nfields;
  fmt->needs = need;
}

/* ---------------------------------------------------------------- */

/* Remove those fields from FMT which would need the proc_stat flags FLAGS.
   Appropiate inter-field characters are also removed: those *following*
   deleted fields at the beginning of the fmt, and those *preceeding* deleted
   fields *not* at the beginning.  */
void
ps_fmt_squash_flags (struct ps_fmt *fmt, ps_flags_t flags)
{
  int squashable_spec (const struct ps_fmt_spec *spec)
    {
      return ps_getter_needs (ps_fmt_spec_getter (spec)) & flags;
    }

  ps_fmt_squash (fmt, squashable_spec);
}

/* ---------------------------------------------------------------- */

/* Try and restrict the number of output columns in FMT to WIDTH.  */
void
ps_fmt_set_output_width (struct ps_fmt *fmt, int width)
{
  struct ps_fmt_field *field = ps_fmt_fields (fmt);
  int nfields = ps_fmt_num_fields (fmt);

  /* We're not very clever about this -- just add up the width of all the
     fields but the last, and if the last has no existing width (as is
     the case in most output formats), give it whatever is left over.  */
  while (--nfields > 0)
    {
      int fw = field->width;
      width -= field->pfx_len + (fw < 0 ? -fw : fw);
      field++;
    }
  if (nfields == 0 && field->width == 0 && width > 0)
    field->width = width - field->pfx_len - 1; /* 1 for the CR. */
}