src/common/header.c

#ifndef lint
static const char       RCSid[] = "$Id: header.c,v 2.50 2025/06/06 19:11:21 greg Exp $";
#endif
/*
 *  header.c - routines for reading and writing information headers.
 *
 *  Externals declared in rtio.h
 *
 *  newheader(t,fp)     start new information header identified by string t
 *  headidval(r,s)      copy header identifier value in s to r
 *  dateval(t,s)        get capture date value as UTC
 *  gmtval(t,s)         get GMT as UTC
 *  fputdate(t,fp)      put out the given UTC
 *  fputnow(fp)         put out the current date and time
 *  formatval(r,s)      copy the format value in s to r
 *  fputformat(s,fp)    write "FORMAT=%s" to fp
 *  nativebigendian()   are we native on big-endian machine?
 *  isbigendian(s)      header line matches "BigEndian=1" (-1 if irrelevant)
 *  fputendian(fp)      write native endianness in BigEndian= line
 *  getheader(fp,f,p)   read header from fp, calling f(s,p) on each line
 *  globmatch(pat, str) check for glob match of str against pat
 *  checkheader(i,p,o)  check header format from i against p and copy to o
 *
 *  To copy header from input to output, use getheader(fin, fputs, fout)
 */

#include "copyright.h"

#include  <ctype.h>

#include  "tiff.h"      /* for int32 */
#include  "rtio.h"
#include  "color.h"
#include  "resolu.h"

#define  MAXLINE        2048

extern time_t           timegm(struct tm *tm);

const char  HDRSTR[] = "#?";            /* information header magic number */

const char  FMTSTR[] = "FORMAT=";       /* format identifier */

const char  TMSTR[] = "CAPDATE=";       /* capture date identifier */
const char  GMTSTR[] = "GMT=";          /* GMT identifier */

const char  BIGEND[] = "BigEndian=";    /* big-endian variable */

static gethfunc mycheck;


void
newheader(              /* identifying line of information header */
        const char  *s,
        FILE  *fp
)
{
        fputs(HDRSTR, fp);
        fputs(s, fp);
        fputc('\n', fp);
}


int
headidval(                      /* get header id (return true if is id) */
        char  *r,
        const char      *s
)
{
        const char  *cp = HDRSTR;

        while (*cp) if (*cp++ != *s++) return(0);
        if (r == NULL) return(1);
        while (*s && !isspace(*s)) *r++ = *s++;
        *r = '\0';
        return(1);
}


int
dateval(                /* convert capture date line to UTC */
        time_t  *tloc,
        const char      *s
)
{
        struct tm       tms;
        const char      *cp = TMSTR;

        while (*cp) if (*cp++ != *s++) return(0);
        while (isspace(*s)) s++;
        if (!*s) return(0);
        if (sscanf(s, "%d:%d:%d %d:%d:%d",
                        &tms.tm_year, &tms.tm_mon, &tms.tm_mday,
                        &tms.tm_hour, &tms.tm_min, &tms.tm_sec) != 6)
                return(0);
        if (tloc == NULL)
                return(1);
        tms.tm_mon--;
        tms.tm_year -= 1900;
        tms.tm_isdst = -1;      /* ask mktime() to figure out DST */
        *tloc = mktime(&tms);
        return(1);
}


int
gmtval(                 /* convert GMT date line to UTC */
        time_t  *tloc,
        const char      *s
)
{
        struct tm       tms;
        const char      *cp = GMTSTR;

        while (*cp) if (*cp++ != *s++) return(0);
        while (isspace(*s)) s++;
        if (!*s) return(0);
        if (sscanf(s, "%d:%d:%d %d:%d:%d",
                        &tms.tm_year, &tms.tm_mon, &tms.tm_mday,
                        &tms.tm_hour, &tms.tm_min, &tms.tm_sec) != 6)
                return(0);
        if (tloc == NULL)
                return(1);
        tms.tm_mon--;
        tms.tm_year -= 1900;
        *tloc = timegm(&tms);
        return(1);
}


void
fputdate(               /* write out the given time value (local & GMT) */
        time_t  tv,
        FILE    *fp
)
{
        struct tm       *tms;

        tms = localtime(&tv);
        if (tms != NULL)
                fprintf(fp, "%s %04d:%02d:%02d %02d:%02d:%02d\n", TMSTR,
                                tms->tm_year+1900, tms->tm_mon+1, tms->tm_mday,
                                tms->tm_hour, tms->tm_min, tms->tm_sec);
        tms = gmtime(&tv);
        if (tms != NULL)
                fprintf(fp, "%s %04d:%02d:%02d %02d:%02d:%02d\n", GMTSTR,
                                tms->tm_year+1900, tms->tm_mon+1, tms->tm_mday,
                                tms->tm_hour, tms->tm_min, tms->tm_sec);
}


void
fputnow(                        /* write out the current time */
        FILE    *fp
)
{
        time_t  tv;
        time(&tv);
        fputdate(tv, fp);
}


int
formatval(                      /* get format value (return true if format) */
        char  fmt[MAXFMTLEN],
        const char  *s
)
{
        const char  *cp = FMTSTR;
        char  *r = fmt;
                                /* check against format string */
        while (*cp) if (*cp++ != *s++) return(0);
        while (isspace(*s)) s++;
        if (!*s) return(0);
        if (r == NULL)          /* just checking if format? */
                return(1);
        do                      /* copy format ID */
                *r++ = *s++;
        while (*s && r-fmt < MAXFMTLEN-1);

        do                      /* remove trailing white space */
                *r-- = '\0';
        while (r > fmt && isspace(*r));

        return(1);
}


void
fputformat(             /* put out a format value */
        const char  *s,
        FILE  *fp
)
{
        int     align = 0;

        fputs(FMTSTR, fp);
        fputs(s, fp);
                        /* pad to align binary type for mmap() */
        if (globmatch(PICFMT, s))
                align = 0;      /* not needed for picture data */
        else if (!strncmp("float", s, 5))
                align = sizeof(float);
        else if (!strncmp("double", s, 6))
                align = sizeof(double);
        else if (!strncmp("16-bit", s, 6))
                align = 2;
        else if (!strncmp("32-bit", s, 6))
                align = 4;
        else if (!strncmp("64-bit", s, 6))
                align = 8;
        if (align) {
                long    pos = ftell(fp);
                if (pos >= 0) {
                        pos = (pos + 2) % align;
                        if (pos) align -= pos;
                        else align = 0;
                } else
                        align = 0;
        }
        while (align-- > 0)
                putc(' ', fp);
        fputc('\n', fp);
}


int
nativebigendian()       /* are we native on a big-endian machine? */
{
        union { int32 i; char c[4]; } u;

        u.i = 1;

        return(u.c[0] == 0);
}


int
isbigendian(            /* header line says "BigEndian=1" (-1 if irrelevant) */
        const char *s
)
{
        const char      *be = BIGEND;

        while ((*s != '\0') & (*be != '=') && *s++ == *be)
                ++be;
        if (*be != '=')
                return(-1);     /* irrelevant */
        while (isspace(*s))
                s++;
        if (*s++ != '=')
                return(-1);
        while (isspace(*s))
                s++;
        return(*s == '1');
}


void
fputendian(             /* write native endianness in BigEndian= line */
        FILE *fp
)
{
        fputs(BIGEND, fp);
        if (nativebigendian())
                fputs("1\n", fp);
        else
                fputs("0\n", fp);
}


int
getheader(              /* get header from file */
        FILE  *fp,
        gethfunc *f,
        void  *p
)
{
        int   rtotal = 0;
        char  buf[MAXLINE];
        int   firstc = fgetc(fp);

        if (!isprint(firstc))
                return(-1);                             /* messed up */
        ungetc(firstc, fp);
        for ( ; ; ) {
                int     rval = 0;
                buf[MAXLINE-2] = '\n';
                if (fgets(buf, MAXLINE, fp) == NULL)
                        return(-1);
                if (buf[buf[0]=='\r'] == '\n')          /* end of header? */
                        return(rtotal);
                if (buf[MAXLINE-2] != '\n') {
                        ungetc(buf[MAXLINE-2], fp);     /* prevent false end */
                        buf[MAXLINE-2] = '\0';
                }
                if (f != NULL && (rval = (*f)(buf, p)) < 0)
                        return(-1);
                rtotal += rval;
        }
}


struct check {
        FILE    *fp;
        char    fs[MAXFMTLEN];
};


static int
mycheck(                        /* check a header line for format info. */
        char  *s,
        void  *cp
)
{
        struct check    *scp = (struct check *)cp;

        if (!formatval(scp->fs, s) && scp->fp != NULL)
                return(fputs(s, scp->fp));

        return(0);
}


int
globmatch(                      /* check for match of s against pattern p */
        const char      *p,
        const char      *s
)
{
        int     setmatch;

        do {
                switch (*p) {
                case '?':                       /* match any character */
                        if (!*s++)
                                return(0);
                        break;
                case '*':                       /* match any string */
                        while (p[1] == '*') p++;
                        do
                                if ( (p[1]=='?') | (p[1]==*s) &&
                                                globmatch(p+1,s) )
                                        return(1);
                        while (*s++);
                        return(0);
                case '[':                       /* character set */
                        setmatch = (*s == *++p);
                        if (!*p)
                                return(0);
                        while (*++p != ']') {
                                if (!*p)
                                        return(0);
                                if (*p == '-') {
                                        setmatch += (p[-1] <= *s) & (*s <= p[1]);
                                        if (!*++p)
                                                break;
                                } else
                                        setmatch += (*p == *s);
                        }
                        if (!setmatch)
                                return(0);
                        s++;
                        break;
                case '\\':                      /* literal next */
                        if (!*++p)
                                return(0);
                /* fall through */
                default:                        /* normal character */
                        if (*p != *s)
                                return(0);
                        s++;
                        break;
                }
        } while (*p++);
        return(1);
}


/*
 * Checkheader(fin,fmt,fout) returns a value of 1 if the input format
 * matches the specification in fmt, 0 if no input format was found,
 * and -1 if the input format does not match or there is an
 * error reading the header.  If fmt is empty, then -1 is returned
 * if any input format is found (or there is an error), and 0 otherwise.
 * If fmt contains any '*' or '?' characters, then checkheader
 * does wildcard expansion and copies a matching result into fmt.
 * Be sure that fmt is big enough to hold the match in such cases,
 * and that it is not a static, read-only string!
 * The input header (minus any format lines) is copied to fout
 * if fout is not NULL.
 */

int
checkheader(
        FILE  *fin,
        char  fmt[MAXFMTLEN],
        FILE  *fout
)
{
        struct check    cdat;
        char    *cp;

        cdat.fp = fout;
        cdat.fs[0] = '\0';
        if (getheader(fin, mycheck, &cdat) < 0)
                return(-1);
        if (!cdat.fs[0])
                return(0);
        for (cp = fmt; *cp; cp++)               /* check for globbing */
                if ((*cp == '?') | (*cp == '*')) {
                        if (globmatch(fmt, cdat.fs)) {
                                strcpy(fmt, cdat.fs);
                                return(1);
                        } else
                                return(-1);
                }
        return(strcmp(fmt, cdat.fs) ? -1 : 1);  /* literal match */
}
Revision:	2.51
Committed:	Sat Jun 7 05:09:45 2025 UTC (17 hours, 54 minutes ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 2.50:	+1 -27 lines
Log Message:	refactor: Put some declarations into "paths.h" and included in "platform.h"
#	User	Rev	Content
1	greg	1.1	#ifndef lint
2	greg	2.51	static const char RCSid[] = "$Id: header.c,v 2.50 2025/06/06 19:11:21 greg Exp $";
3	greg	1.1	#endif
4			/*
5			* header.c - routines for reading and writing information headers.
6			*
7	greg	2.35	* Externals declared in rtio.h
8	greg	1.3	*
9	greg	2.4	* newheader(t,fp) start new information header identified by string t
10			* headidval(r,s) copy header identifier value in s to r
11	greg	2.25	* dateval(t,s) get capture date value as UTC
12			* gmtval(t,s) get GMT as UTC
13			* fputdate(t,fp) put out the given UTC
14	greg	2.11	* fputnow(fp) put out the current date and time
15	greg	1.3	* formatval(r,s) copy the format value in s to r
16			* fputformat(s,fp) write "FORMAT=%s" to fp
17	greg	2.36	* nativebigendian() are we native on big-endian machine?
18			* isbigendian(s) header line matches "BigEndian=1" (-1 if irrelevant)
19			* fputendian(fp) write native endianness in BigEndian= line
20	greg	1.3	* getheader(fp,f,p) read header from fp, calling f(s,p) on each line
21	greg	2.6	* globmatch(pat, str) check for glob match of str against pat
22	greg	1.3	* checkheader(i,p,o) check header format from i against p and copy to o
23			*
24			* To copy header from input to output, use getheader(fin, fputs, fout)
25	greg	1.1	*/
26
27	greg	2.12	#include "copyright.h"
28	greg	2.11
29	greg	1.3	#include <ctype.h>
30	schorsch	2.17
31	greg	2.36	#include "tiff.h" /* for int32 */
32	greg	2.18	#include "rtio.h"
33	greg	2.44	#include "color.h"
34	greg	2.18	#include "resolu.h"
35	schorsch	2.14
36	greg	2.24	#define MAXLINE 2048
37	greg	2.2
38	greg	2.26	extern time_t timegm(struct tm *tm);
39
40	greg	2.25	const char HDRSTR[] = "#?"; /* information header magic number */
41	greg	1.2
42	greg	2.25	const char FMTSTR[] = "FORMAT="; /* format identifier */
43	greg	1.2
44	greg	2.25	const char TMSTR[] = "CAPDATE="; /* capture date identifier */
45			const char GMTSTR[] = "GMT="; /* GMT identifier */
46	greg	2.16
47	greg	2.36	const char BIGEND[] = "BigEndian="; /* big-endian variable */
48
49	schorsch	2.22	static gethfunc mycheck;
50	greg	2.4
51	greg	2.11
52	greg	2.29	void
53	schorsch	2.22	newheader( /* identifying line of information header */
54	greg	2.31	const char *s,
55	greg	2.25	FILE *fp
56	schorsch	2.22	)
57	greg	2.4	{
58			fputs(HDRSTR, fp);
59			fputs(s, fp);
60	greg	2.41	fputc('\n', fp);
61	greg	2.4	}
62
63
64	greg	2.29	int
65	schorsch	2.22	headidval( /* get header id (return true if is id) */
66	greg	2.25	char *r,
67	greg	2.31	const char *s
68	schorsch	2.22	)
69	greg	2.4	{
70	greg	2.25	const char *cp = HDRSTR;
71	greg	2.4
72			while (cp) if (cp++ != *s++) return(0);
73			if (r == NULL) return(1);
74	gregl	2.9	while (s && !isspace(s)) r++ = s++;
75	greg	2.4	*r = '\0';
76			return(1);
77			}
78
79
80	greg	2.29	int
81	greg	2.25	dateval( /* convert capture date line to UTC */
82	schorsch	2.22	time_t *tloc,
83	greg	2.31	const char *s
84	schorsch	2.22	)
85	greg	2.11	{
86			struct tm tms;
87	greg	2.25	const char *cp = TMSTR;
88	greg	2.11
89			while (cp) if (cp++ != *s++) return(0);
90			while (isspace(*s)) s++;
91			if (!*s) return(0);
92			if (sscanf(s, "%d:%d:%d %d:%d:%d",
93			&tms.tm_year, &tms.tm_mon, &tms.tm_mday,
94			&tms.tm_hour, &tms.tm_min, &tms.tm_sec) != 6)
95			return(0);
96			if (tloc == NULL)
97			return(1);
98			tms.tm_mon--;
99			tms.tm_year -= 1900;
100			tms.tm_isdst = -1; /* ask mktime() to figure out DST */
101			*tloc = mktime(&tms);
102			return(1);
103			}
104
105
106	greg	2.29	int
107	greg	2.25	gmtval( /* convert GMT date line to UTC */
108			time_t *tloc,
109	greg	2.31	const char *s
110	schorsch	2.22	)
111	greg	2.11	{
112	greg	2.25	struct tm tms;
113			const char *cp = GMTSTR;
114
115			while (cp) if (cp++ != *s++) return(0);
116			while (isspace(*s)) s++;
117			if (!*s) return(0);
118			if (sscanf(s, "%d:%d:%d %d:%d:%d",
119			&tms.tm_year, &tms.tm_mon, &tms.tm_mday,
120			&tms.tm_hour, &tms.tm_min, &tms.tm_sec) != 6)
121			return(0);
122			if (tloc == NULL)
123			return(1);
124			tms.tm_mon--;
125			tms.tm_year -= 1900;
126			*tloc = timegm(&tms);
127			return(1);
128	greg	2.11	}
129
130
131	greg	2.29	void
132	greg	2.25	fputdate( /* write out the given time value (local & GMT) */
133	schorsch	2.22	time_t tv,
134			FILE *fp
135			)
136	greg	2.11	{
137	greg	2.25	struct tm *tms;
138
139			tms = localtime(&tv);
140			if (tms != NULL)
141			fprintf(fp, "%s %04d:%02d:%02d %02d:%02d:%02d\n", TMSTR,
142			tms->tm_year+1900, tms->tm_mon+1, tms->tm_mday,
143			tms->tm_hour, tms->tm_min, tms->tm_sec);
144			tms = gmtime(&tv);
145			if (tms != NULL)
146			fprintf(fp, "%s %04d:%02d:%02d %02d:%02d:%02d\n", GMTSTR,
147			tms->tm_year+1900, tms->tm_mon+1, tms->tm_mday,
148			tms->tm_hour, tms->tm_min, tms->tm_sec);
149	greg	2.11	}
150
151
152	greg	2.29	void
153	schorsch	2.22	fputnow( /* write out the current time */
154			FILE *fp
155			)
156	greg	2.11	{
157			time_t tv;
158			time(&tv);
159			fputdate(tv, fp);
160			}
161
162
163	greg	2.29	int
164	schorsch	2.22	formatval( /* get format value (return true if format) */
165	greg	2.32	char fmt[MAXFMTLEN],
166	greg	2.31	const char *s
167	schorsch	2.22	)
168	greg	1.2	{
169	greg	2.25	const char *cp = FMTSTR;
170	greg	2.32	char *r = fmt;
171	greg	2.48	/* check against format string */
172	greg	2.4	while (cp) if (cp++ != *s++) return(0);
173	greg	1.3	while (isspace(*s)) s++;
174	greg	2.4	if (!*s) return(0);
175	greg	2.48	if (r == NULL) /* just checking if format? */
176			return(1);
177			do /* copy format ID */
178	greg	2.5	r++ = s++;
179	greg	2.48	while (*s && r-fmt < MAXFMTLEN-1);
180
181			do /* remove trailing white space */
182			*r-- = '\0';
183			while (r > fmt && isspace(*r));
184
185	greg	2.4	return(1);
186	greg	1.2	}
187
188
189	greg	2.29	void
190	schorsch	2.22	fputformat( /* put out a format value */
191	greg	2.31	const char *s,
192	schorsch	2.22	FILE *fp
193			)
194	greg	1.2	{
195	greg	2.41	int align = 0;
196
197	greg	1.2	fputs(FMTSTR, fp);
198			fputs(s, fp);
199	greg	2.41	/* pad to align binary type for mmap() */
200	greg	2.44	if (globmatch(PICFMT, s))
201			align = 0; /* not needed for picture data */
202			else if (!strncmp("float", s, 5))
203	greg	2.43	align = sizeof(float);
204	greg	2.44	else if (!strncmp("double", s, 6))
205	greg	2.43	align = sizeof(double);
206	greg	2.44	else if (!strncmp("16-bit", s, 6))
207	greg	2.42	align = 2;
208	greg	2.44	else if (!strncmp("32-bit", s, 6))
209	greg	2.41	align = 4;
210	greg	2.44	else if (!strncmp("64-bit", s, 6))
211	greg	2.41	align = 8;
212			if (align) {
213			long pos = ftell(fp);
214			if (pos >= 0) {
215			pos = (pos + 2) % align;
216			if (pos) align -= pos;
217			else align = 0;
218			} else
219			align = 0;
220			}
221			while (align-- > 0)
222			putc(' ', fp);
223			fputc('\n', fp);
224	greg	1.2	}
225
226
227	greg	2.29	int
228	greg	2.36	nativebigendian() /* are we native on a big-endian machine? */
229			{
230			union { int32 i; char c[4]; } u;
231
232			u.i = 1;
233
234			return(u.c[0] == 0);
235			}
236
237
238			int
239			isbigendian( /* header line says "BigEndian=1" (-1 if irrelevant) */
240			const char *s
241			)
242			{
243			const char *be = BIGEND;
244
245	greg	2.37	while ((s != '\0') & (be != '=') && s++ == be)
246	greg	2.36	++be;
247			if (*be != '=')
248			return(-1); /* irrelevant */
249			while (isspace(*s))
250			s++;
251			if (*s++ != '=')
252			return(-1);
253			while (isspace(*s))
254			s++;
255			return(*s == '1');
256			}
257
258
259			void
260			fputendian( /* write native endianness in BigEndian= line */
261			FILE *fp
262			)
263			{
264			fputs(BIGEND, fp);
265			if (nativebigendian())
266			fputs("1\n", fp);
267			else
268			fputs("0\n", fp);
269			}
270
271
272			int
273	schorsch	2.22	getheader( /* get header from file */
274			FILE *fp,
275			gethfunc *f,
276			void *p
277			)
278	greg	1.1	{
279	greg	2.30	int rtotal = 0;
280	greg	1.1	char buf[MAXLINE];
281	greg	2.34	int firstc = fgetc(fp);
282	greg	1.1
283	greg	2.34	if (!isprint(firstc))
284			return(-1); /* messed up */
285			ungetc(firstc, fp);
286	greg	1.1	for ( ; ; ) {
287	greg	2.30	int rval = 0;
288	greg	1.1	buf[MAXLINE-2] = '\n';
289	greg	2.3	if (fgets(buf, MAXLINE, fp) == NULL)
290	greg	1.1	return(-1);
291	greg	2.34	if (buf[buf[0]=='\r'] == '\n') /* end of header? */
292	greg	2.30	return(rtotal);
293	greg	1.1	if (buf[MAXLINE-2] != '\n') {
294			ungetc(buf[MAXLINE-2], fp); /* prevent false end */
295			buf[MAXLINE-2] = '\0';
296			}
297	greg	2.30	if (f != NULL && (rval = (*f)(buf, p)) < 0)
298	gwlarson	2.10	return(-1);
299	greg	2.30	rtotal += rval;
300	greg	1.1	}
301			}
302
303
304	greg	1.2	struct check {
305			FILE *fp;
306	greg	2.32	char fs[MAXFMTLEN];
307	greg	1.2	};
308	greg	1.1
309	greg	1.2
310	greg	2.11	static int
311	schorsch	2.22	mycheck( /* check a header line for format info. */
312			char *s,
313			void *cp
314			)
315			{
316	greg	2.33	struct check scp = (struct check )cp;
317
318			if (!formatval(scp->fs, s) && scp->fp != NULL)
319	greg	2.38	return(fputs(s, scp->fp));
320	greg	2.33
321	greg	2.11	return(0);
322	greg	1.1	}
323
324
325	greg	2.29	int
326	schorsch	2.22	globmatch( /* check for match of s against pattern p */
327	greg	2.31	const char *p,
328			const char *s
329	schorsch	2.22	)
330	greg	1.3	{
331	greg	2.11	int setmatch;
332	greg	1.3
333			do {
334			switch (*p) {
335			case '?': /* match any character */
336			if (!*s++)
337			return(0);
338			break;
339			case '': / match any string */
340			while (p[1] == '*') p++;
341			do
342	greg	2.28	if ( (p[1]=='?') \| (p[1]==*s) &&
343	greg	2.6	globmatch(p+1,s) )
344	greg	1.3	return(1);
345			while (*s++);
346			return(0);
347	greg	2.11	case '[': /* character set */
348	greg	2.46	setmatch = (s == ++p);
349	greg	2.11	if (!*p)
350			return(0);
351			while (*++p != ']') {
352			if (!*p)
353			return(0);
354			if (*p == '-') {
355	greg	2.45	setmatch += (p[-1] <= s) & (s <= p[1]);
356	greg	2.11	if (!*++p)
357			break;
358			} else
359	greg	2.28	setmatch += (p == s);
360	greg	2.11	}
361			if (!setmatch)
362			return(0);
363			s++;
364			break;
365	greg	1.3	case '\\': /* literal next */
366	greg	2.47	if (!*++p)
367			return(0);
368	greg	1.3	/* fall through */
369			default: /* normal character */
370	greg	2.47	if (p != s)
371	greg	1.3	return(0);
372			s++;
373			break;
374			}
375			} while (*p++);
376			return(1);
377			}
378
379
380			/*
381			* Checkheader(fin,fmt,fout) returns a value of 1 if the input format
382			* matches the specification in fmt, 0 if no input format was found,
383			* and -1 if the input format does not match or there is an
384	greg	1.4	* error reading the header. If fmt is empty, then -1 is returned
385	greg	1.3	* if any input format is found (or there is an error), and 0 otherwise.
386			* If fmt contains any '*' or '?' characters, then checkheader
387			* does wildcard expansion and copies a matching result into fmt.
388	greg	2.7	* Be sure that fmt is big enough to hold the match in such cases,
389			* and that it is not a static, read-only string!
390	greg	1.3	* The input header (minus any format lines) is copied to fout
391			* if fout is not NULL.
392			*/
393
394	greg	2.29	int
395	schorsch	2.22	checkheader(
396			FILE *fin,
397	greg	2.32	char fmt[MAXFMTLEN],
398	schorsch	2.22	FILE *fout
399			)
400	greg	1.1	{
401	greg	1.2	struct check cdat;
402	greg	2.25	char *cp;
403	greg	1.2
404			cdat.fp = fout;
405			cdat.fs[0] = '\0';
406	schorsch	2.22	if (getheader(fin, mycheck, &cdat) < 0)
407	greg	1.3	return(-1);
408	greg	2.6	if (!cdat.fs[0])
409			return(0);
410	greg	2.7	for (cp = fmt; cp; cp++) / check for globbing */
411	schorsch	2.20	if ((cp == '?') \| (cp == '*')) {
412	greg	2.7	if (globmatch(fmt, cdat.fs)) {
413			strcpy(fmt, cdat.fs);
414			return(1);
415			} else
416			return(-1);
417	schorsch	2.19	}
418	greg	2.7	return(strcmp(fmt, cdat.fs) ? -1 : 1); /* literal match */
419	greg	1.1	}