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[emacs.git] / src / doprnt.c
blobb0dcc2a7de6ee67ed946bdda1001e9f32e15e8cb
1 /* Output like sprintf to a buffer of specified size.
2 Also takes args differently: pass one pointer to an array of strings
3 in addition to the format string which is separate.
4 Copyright (C) 1985 Free Software Foundation, Inc.
6 This file is part of GNU Emacs.
8 GNU Emacs is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
13 GNU Emacs is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU Emacs; see the file COPYING. If not, write to
20 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 #include <config.h>
25 #include <stdio.h>
26 #include <ctype.h>
28 #ifdef STDC_HEADERS
29 #include <float.h>
30 #endif
32 #ifdef HAVE_UNISTD_H
33 #include <unistd.h>
34 #endif
36 #ifdef HAVE_STDLIB_H
37 #include <stdlib.h>
38 #endif
40 #include "lisp.h"
42 #ifndef DBL_MAX_10_EXP
43 #define DBL_MAX_10_EXP 308 /* IEEE double */
44 #endif
46 /* Since we use the macro CHAR_HEAD_P, we have to include this, but
47 don't have to include others because CHAR_HEAD_P does not contains
48 another macro. */
49 #include "charset.h"
51 static int doprnt1 ();
53 /* Generate output from a format-spec FORMAT,
54 terminated at position FORMAT_END.
55 Output goes in BUFFER, which has room for BUFSIZE chars.
56 If the output does not fit, truncate it to fit.
57 Returns the number of characters stored into BUFFER.
58 ARGS points to the vector of arguments, and NARGS says how many.
59 A double counts as two arguments.
60 String arguments are passed as C strings.
61 Integers are passed as C integers. */
63 int
64 doprnt (buffer, bufsize, format, format_end, nargs, args)
65 char *buffer;
66 register int bufsize;
67 char *format;
68 char *format_end;
69 int nargs;
70 char **args;
72 return doprnt1 (0, buffer, bufsize, format, format_end, nargs, args);
75 /* Like doprnt except that strings in ARGS are passed
76 as Lisp_Object. */
78 int
79 doprnt_lisp (buffer, bufsize, format, format_end, nargs, args)
80 char *buffer;
81 register int bufsize;
82 char *format;
83 char *format_end;
84 int nargs;
85 char **args;
87 return doprnt1 (1, buffer, bufsize, format, format_end, nargs, args);
90 static int
91 doprnt1 (lispstrings, buffer, bufsize, format, format_end, nargs, args)
92 int lispstrings;
93 char *buffer;
94 register int bufsize;
95 char *format;
96 char *format_end;
97 int nargs;
98 char **args;
100 int cnt = 0; /* Number of arg to gobble next */
101 register char *fmt = format; /* Pointer into format string */
102 register char *bufptr = buffer; /* Pointer into output buffer.. */
104 /* Use this for sprintf unless we need something really big. */
105 char tembuf[DBL_MAX_10_EXP + 100];
107 /* Size of sprintf_buffer. */
108 int size_allocated = sizeof (tembuf);
110 /* Buffer to use for sprintf. Either tembuf or same as BIG_BUFFER. */
111 char *sprintf_buffer = tembuf;
113 /* Buffer we have got with malloc. */
114 char *big_buffer = 0;
116 register int tem;
117 unsigned char *string;
118 char fixed_buffer[20]; /* Default buffer for small formatting. */
119 char *fmtcpy;
120 int minlen;
121 int size; /* Field width factor; e.g., %90d */
122 unsigned char charbuf[5]; /* Used for %c. */
124 if (format_end == 0)
125 format_end = format + strlen (format);
127 if ((format_end - format + 1) < sizeof (fixed_buffer))
128 fmtcpy = fixed_buffer;
129 else
130 fmtcpy = (char *) alloca (format_end - format + 1);
132 bufsize--;
134 /* Loop until end of format string or buffer full. */
135 while (fmt != format_end && bufsize > 0)
137 if (*fmt == '%') /* Check for a '%' character */
139 int size_bound = 0;
140 int width; /* Columns occupied by STRING. */
142 fmt++;
143 /* Copy this one %-spec into fmtcpy. */
144 string = (unsigned char *)fmtcpy;
145 *string++ = '%';
146 while (1)
148 *string++ = *fmt;
149 if ('0' <= *fmt && *fmt <= '9')
151 /* Get an idea of how much space we might need.
152 This might be a field width or a precision; e.g.
153 %1.1000f and %1000.1f both might need 1000+ bytes.
154 Parse the width or precision, checking for overflow. */
155 int n = *fmt - '0';
156 while ('0' <= fmt[1] && fmt[1] <= '9')
158 if (n * 10 / 10 != n
159 || (n = n * 10 + (fmt[1] - '0')) < 0)
160 error ("Format width or precision too large");
161 *string++ = *++fmt;
164 if (size_bound < n)
165 size_bound = n;
167 else if (*fmt == '-' || *fmt == ' ' || *fmt == '.')
169 else
170 break;
171 fmt++;
173 *string = 0;
175 /* Make the size bound large enough to handle floating point formats
176 with large numbers. */
177 size_bound += DBL_MAX_10_EXP + 50;
179 if (size_bound < 0)
180 error ("Format width or precision too large");
182 /* Make sure we have that much. */
183 if (size_bound > size_allocated)
185 if (big_buffer)
186 big_buffer = (char *) xrealloc (big_buffer, size_bound);
187 else
188 big_buffer = (char *) xmalloc (size_bound);
189 sprintf_buffer = big_buffer;
190 size_allocated = size_bound;
192 minlen = 0;
193 switch (*fmt++)
195 default:
196 error ("Invalid format operation %%%c", fmt[-1]);
198 /* case 'b': */
199 case 'd':
200 case 'o':
201 case 'x':
202 if (cnt == nargs)
203 error ("Not enough arguments for format string");
204 if (sizeof (int) == sizeof (EMACS_INT))
206 else if (sizeof (long) == sizeof (EMACS_INT))
207 /* Insert an `l' the right place. */
208 string[1] = string[0],
209 string[0] = string[-1],
210 string[-1] = 'l',
211 string++;
212 else
213 abort ();
214 sprintf (sprintf_buffer, fmtcpy, args[cnt++]);
215 /* Now copy into final output, truncating as nec. */
216 string = (unsigned char *)sprintf_buffer;
217 goto doit;
219 case 'f':
220 case 'e':
221 case 'g':
223 union { double d; char *half[2]; } u;
224 if (cnt + 1 == nargs)
225 error ("not enough arguments for format string");
226 u.half[0] = args[cnt++];
227 u.half[1] = args[cnt++];
228 sprintf (sprintf_buffer, fmtcpy, u.d);
229 /* Now copy into final output, truncating as nec. */
230 string = (unsigned char *)sprintf_buffer;
231 goto doit;
234 case 'S':
235 string[-1] = 's';
236 case 's':
237 if (cnt == nargs)
238 error ("not enough arguments for format string");
239 if (fmtcpy[1] != 's')
240 minlen = atoi (&fmtcpy[1]);
241 if (lispstrings)
243 string = ((struct Lisp_String *)args[cnt])->data;
244 tem = ((struct Lisp_String *)args[cnt])->size;
245 cnt++;
247 else
249 string = (unsigned char *)args[cnt++];
250 tem = strlen (string);
252 width = strwidth (string, tem);
253 goto doit1;
255 /* Copy string into final output, truncating if no room. */
256 doit:
257 /* Coming here means STRING contains ASCII only. */
258 width = tem = strlen (string);
259 doit1:
260 /* We have already calculated:
261 TEM -- length of STRING,
262 WIDTH -- columns occupied by STRING when displayed, and
263 MINLEN -- minimum columns of the output. */
264 if (minlen > 0)
266 while (minlen > width && bufsize > 0)
268 *bufptr++ = ' ';
269 bufsize--;
270 minlen--;
272 minlen = 0;
274 if (tem > bufsize)
276 /* Truncate the string at character boundary. */
277 tem = bufsize;
278 while (!CHAR_HEAD_P (string[tem - 1])) tem--;
279 bcopy (string, bufptr, tem);
280 /* We must calculate WIDTH again. */
281 width = strwidth (bufptr, tem);
283 else
284 bcopy (string, bufptr, tem);
285 bufptr += tem;
286 bufsize -= tem;
287 if (minlen < 0)
289 while (minlen < - width && bufsize > 0)
291 *bufptr++ = ' ';
292 bufsize--;
293 minlen++;
295 minlen = 0;
297 continue;
299 case 'c':
300 if (cnt == nargs)
301 error ("not enough arguments for format string");
302 tem = CHAR_STRING ((int) (EMACS_INT) args[cnt], charbuf);
303 string = charbuf;
304 cnt++;
305 string[tem] = 0;
306 width = strwidth (string, tem);
307 if (fmtcpy[1] != 'c')
308 minlen = atoi (&fmtcpy[1]);
309 goto doit1;
311 case '%':
312 fmt--; /* Drop thru and this % will be treated as normal */
317 /* Just some character; Copy it if the whole multi-byte form
318 fit in the buffer. */
319 char *save_bufptr = bufptr;
321 do { *bufptr++ = *fmt++; }
322 while (--bufsize > 0 && !CHAR_HEAD_P (*fmt));
323 if (!CHAR_HEAD_P (*fmt))
325 bufptr = save_bufptr;
326 break;
331 /* If we had to malloc something, free it. */
332 if (big_buffer)
333 xfree (big_buffer);
335 *bufptr = 0; /* Make sure our string end with a '\0' */
336 return bufptr - buffer;