/* External procedures for dvitype				*/
/*   Written by: H. Trickey, 2/19/83 (adapted from TeX's ext.c) */

#include "texpaths.h"	/* defines default TEXFONTS path */
#include "h00vars.h"		/* defines Pascal I/O structure */

char *fontpath;

char *getenv();

/*
 * setpaths is called to set up the pointer fontpath
 * as follows:  if the user's environment has a value for TEXFONTS
 * then use it;  otherwise, use defaultfontpath.
 */
setpaths()
{
	register char *envpath;
	
	if ((envpath = getenv("TEXFONTS")) != NULL)
	    fontpath = envpath;
	else
	    fontpath = defaultfontpath;
}

#define namelength 100   /* should agree with defn in textyl program*/
extern char thefilename[],realnameoffile[]; /* these have size namelength */

/*
 *	testaccess(amode,filepath)
 *
 *  Test whether or not the file whose name is in the global thefilename
 *  can be opened for reading (if mode=READACCESS)
 *  or writing (if mode=WRITEACCESS).
 *
 *  The filepath argument is one of the ...FILEPATH constants defined below.
 *  If the filename given in thefilename does not begin with '/', we try 
 *  prepending all the ':'-separated areanames in the appropriate path to the
 *  filename until access can be made, if it ever can.
 *
 *  The realnameoffile global array will contain the name that yielded an
 *  access success.
 */

#define READACCESS 4
#define WRITEACCESS 2

#define NOFILEPATH 0
#define FONTFILEPATH 3

bool
testaccess(amode,filepath)
    int amode,filepath;
{
    register    bool ok;
    register char  *p;
    char   *curpathplace;
    int     f;

    switch (filepath) {
	case NOFILEPATH: 
	    curpathplace = NULL;
	    break;
	case FONTFILEPATH: 
	    curpathplace = fontpath;
	    break;
    }
    if (thefilename[0] == '/')	/* file name has absolute path */
	curpathplace = NULL;
    do {
	packrealnameoffile (&curpathplace);
	if (amode == READACCESS)/* use system call "access" to see if we
				   could read it */
	    if (access (realnameoffile, READACCESS) == 0)
		ok = TRUE;
	    else
		ok = FALSE;
	else {
	/* WRITEACCESS: use creat to see if we could create it, but close
	   the file again if we''re OK, to let pc open it for real */
	    f = creat (realnameoffile, 0666);
	    if (f >= 0)
		ok = TRUE;
	    else
		ok = FALSE;
	    if (ok)
		close (f);
	}
    } while (!ok && curpathplace != NULL);
    if (ok) {			/* pad realnameoffile with blanks, as
				   Pascal wants */
	for (p = realnameoffile; *p != '\0'; p++)
				/* nothing: find end of string */
	    ;
	while (p < &(realnameoffile[namelength]))
	    *p++ = ' ';
    }
    return (ok);
}

/*
 * packrealnameoffile(cpp) makes realnameoffile contain the directory at *cpp,
 * followed by '/', followed by the characters in thefilename up until the
 * first blank there, and finally a '\0'.  The cpp pointer is left pointing
 * at the next directory in the path.
 * But: if *cpp == NULL, then we are supposed to use thefilename as is.
 */
packrealnameoffile(cpp)
    char **cpp;
{
    register char  *p,
                   *realname;

    realname = realnameoffile;
    if ((p = *cpp) != NULL) {
	while ((*p != ':') && (*p != '\0')) {
	    *realname++ = *p++;
	    if (realname == &(realnameoffile[namelength - 1]))
		break;
	}
	if (*p == '\0')
	    *cpp = NULL;	/* at end of path now */
	else
	    *cpp = p + 1;	/* else get past ':' */
	*realname++ = '/';	/* separate the area from the name to
				   follow */
    }
 /* now append thefilename to realname... */
    p = thefilename;
    while (*p != ' ') {
	if (realname >= &(realnameoffile[namelength - 1])) {
	    fprintf (stderr, "! Full file name is too long\n");
	    break;
	}
	*realname++ = *p++;
    }
    *realname = '\0';
}