Annotation of 42BSD/ucb/vgrind/vgrindefs.c, revision 1.1.1.1

1.1       root        1: #ifndef lint
                      2: static char sccsid[] = "@(#)vgrindefs.c        4.2 (Berkeley) 7/2/83";
                      3: #endif
                      4: 
                      5: /* Copyright (c) 1979 Regents of the University of California */
                      6: 
                      7: #define        BUFSIZ  1024
                      8: #define MAXHOP 32      /* max number of tc= indirections */
                      9: 
                     10: #include <ctype.h>
                     11: /*
                     12:  * grindcap - routines for dealing with the language definitions data base
                     13:  *     (code stolen almost totally from termcap)
                     14:  *
                     15:  * BUG:                Should use a "last" pointer in tbuf, so that searching
                     16:  *             for capabilities alphabetically would not be a n**2/2
                     17:  *             process when large numbers of capabilities are given.
                     18:  * Note:       If we add a last pointer now we will screw up the
                     19:  *             tc capability. We really should compile termcap.
                     20:  *
                     21:  * Essentially all the work here is scanning and decoding escapes
                     22:  * in string capabilities.  We don't use stdio because the editor
                     23:  * doesn't, and because living w/o it is not hard.
                     24:  */
                     25: 
                     26: static char *tbuf;
                     27: static int hopcount;   /* detect infinite loops in termcap, init 0 */
                     28: char   *tskip();
                     29: char   *tgetstr();
                     30: char   *tdecode();
                     31: char   *getenv();
                     32: 
                     33: /*
                     34:  * Get an entry for terminal name in buffer bp,
                     35:  * from the termcap file.  Parse is very rudimentary;
                     36:  * we just notice escaped newlines.
                     37:  */
                     38: tgetent(bp, name, filename)
                     39:        char *bp, *name, *filename;
                     40: {
                     41:        register char *cp;
                     42:        register int c;
                     43:        register int i = 0, cnt = 0;
                     44:        char ibuf[BUFSIZ];
                     45:        char *cp2;
                     46:        int tf;
                     47: 
                     48:        tbuf = bp;
                     49:        tf = 0;
                     50:        tf = open(filename, 0);
                     51:        if (tf < 0)
                     52:                return (-1);
                     53:        for (;;) {
                     54:                cp = bp;
                     55:                for (;;) {
                     56:                        if (i == cnt) {
                     57:                                cnt = read(tf, ibuf, BUFSIZ);
                     58:                                if (cnt <= 0) {
                     59:                                        close(tf);
                     60:                                        return (0);
                     61:                                }
                     62:                                i = 0;
                     63:                        }
                     64:                        c = ibuf[i++];
                     65:                        if (c == '\n') {
                     66:                                if (cp > bp && cp[-1] == '\\'){
                     67:                                        cp--;
                     68:                                        continue;
                     69:                                }
                     70:                                break;
                     71:                        }
                     72:                        if (cp >= bp+BUFSIZ) {
                     73:                                write(2,"Vgrind entry too long\n", 23);
                     74:                                break;
                     75:                        } else
                     76:                                *cp++ = c;
                     77:                }
                     78:                *cp = 0;
                     79: 
                     80:                /*
                     81:                 * The real work for the match.
                     82:                 */
                     83:                if (tnamatch(name)) {
                     84:                        close(tf);
                     85:                        return(tnchktc());
                     86:                }
                     87:        }
                     88: }
                     89: 
                     90: /*
                     91:  * tnchktc: check the last entry, see if it's tc=xxx. If so,
                     92:  * recursively find xxx and append that entry (minus the names)
                     93:  * to take the place of the tc=xxx entry. This allows termcap
                     94:  * entries to say "like an HP2621 but doesn't turn on the labels".
                     95:  * Note that this works because of the left to right scan.
                     96:  */
                     97: tnchktc()
                     98: {
                     99:        register char *p, *q;
                    100:        char tcname[16];        /* name of similar terminal */
                    101:        char tcbuf[BUFSIZ];
                    102:        char *holdtbuf = tbuf;
                    103:        int l;
                    104: 
                    105:        p = tbuf + strlen(tbuf) - 2;    /* before the last colon */
                    106:        while (*--p != ':')
                    107:                if (p<tbuf) {
                    108:                        write(2, "Bad vgrind entry\n", 18);
                    109:                        return (0);
                    110:                }
                    111:        p++;
                    112:        /* p now points to beginning of last field */
                    113:        if (p[0] != 't' || p[1] != 'c')
                    114:                return(1);
                    115:        strcpy(tcname,p+3);
                    116:        q = tcname;
                    117:        while (q && *q != ':')
                    118:                q++;
                    119:        *q = 0;
                    120:        if (++hopcount > MAXHOP) {
                    121:                write(2, "Infinite tc= loop\n", 18);
                    122:                return (0);
                    123:        }
                    124:        if (tgetent(tcbuf, tcname) != 1)
                    125:                return(0);
                    126:        for (q=tcbuf; *q != ':'; q++)
                    127:                ;
                    128:        l = p - holdtbuf + strlen(q);
                    129:        if (l > BUFSIZ) {
                    130:                write(2, "Vgrind entry too long\n", 23);
                    131:                q[BUFSIZ - (p-tbuf)] = 0;
                    132:        }
                    133:        strcpy(p, q+1);
                    134:        tbuf = holdtbuf;
                    135:        return(1);
                    136: }
                    137: 
                    138: /*
                    139:  * Tnamatch deals with name matching.  The first field of the termcap
                    140:  * entry is a sequence of names separated by |'s, so we compare
                    141:  * against each such name.  The normal : terminator after the last
                    142:  * name (before the first field) stops us.
                    143:  */
                    144: tnamatch(np)
                    145:        char *np;
                    146: {
                    147:        register char *Np, *Bp;
                    148: 
                    149:        Bp = tbuf;
                    150:        if (*Bp == '#')
                    151:                return(0);
                    152:        for (;;) {
                    153:                for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
                    154:                        continue;
                    155:                if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
                    156:                        return (1);
                    157:                while (*Bp && *Bp != ':' && *Bp != '|')
                    158:                        Bp++;
                    159:                if (*Bp == 0 || *Bp == ':')
                    160:                        return (0);
                    161:                Bp++;
                    162:        }
                    163: }
                    164: 
                    165: /*
                    166:  * Skip to the next field.  Notice that this is very dumb, not
                    167:  * knowing about \: escapes or any such.  If necessary, :'s can be put
                    168:  * into the termcap file in octal.
                    169:  */
                    170: static char *
                    171: tskip(bp)
                    172:        register char *bp;
                    173: {
                    174: 
                    175:        while (*bp && *bp != ':')
                    176:                bp++;
                    177:        if (*bp == ':')
                    178:                bp++;
                    179:        return (bp);
                    180: }
                    181: 
                    182: /*
                    183:  * Return the (numeric) option id.
                    184:  * Numeric options look like
                    185:  *     li#80
                    186:  * i.e. the option string is separated from the numeric value by
                    187:  * a # character.  If the option is not found we return -1.
                    188:  * Note that we handle octal numbers beginning with 0.
                    189:  */
                    190: tgetnum(id)
                    191:        char *id;
                    192: {
                    193:        register int i, base;
                    194:        register char *bp = tbuf;
                    195: 
                    196:        for (;;) {
                    197:                bp = tskip(bp);
                    198:                if (*bp == 0)
                    199:                        return (-1);
                    200:                if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
                    201:                        continue;
                    202:                if (*bp == '@')
                    203:                        return(-1);
                    204:                if (*bp != '#')
                    205:                        continue;
                    206:                bp++;
                    207:                base = 10;
                    208:                if (*bp == '0')
                    209:                        base = 8;
                    210:                i = 0;
                    211:                while (isdigit(*bp))
                    212:                        i *= base, i += *bp++ - '0';
                    213:                return (i);
                    214:        }
                    215: }
                    216: 
                    217: /*
                    218:  * Handle a flag option.
                    219:  * Flag options are given "naked", i.e. followed by a : or the end
                    220:  * of the buffer.  Return 1 if we find the option, or 0 if it is
                    221:  * not given.
                    222:  */
                    223: tgetflag(id)
                    224:        char *id;
                    225: {
                    226:        register char *bp = tbuf;
                    227: 
                    228:        for (;;) {
                    229:                bp = tskip(bp);
                    230:                if (!*bp)
                    231:                        return (0);
                    232:                if (*bp++ == id[0] && *bp != 0 && *bp++ == id[1]) {
                    233:                        if (!*bp || *bp == ':')
                    234:                                return (1);
                    235:                        else if (*bp == '@')
                    236:                                return(0);
                    237:                }
                    238:        }
                    239: }
                    240: 
                    241: /*
                    242:  * Get a string valued option.
                    243:  * These are given as
                    244:  *     cl=^Z
                    245:  * Much decoding is done on the strings, and the strings are
                    246:  * placed in area, which is a ref parameter which is updated.
                    247:  * No checking on area overflow.
                    248:  */
                    249: char *
                    250: tgetstr(id, area)
                    251:        char *id, **area;
                    252: {
                    253:        register char *bp = tbuf;
                    254: 
                    255:        for (;;) {
                    256:                bp = tskip(bp);
                    257:                if (!*bp)
                    258:                        return (0);
                    259:                if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
                    260:                        continue;
                    261:                if (*bp == '@')
                    262:                        return(0);
                    263:                if (*bp != '=')
                    264:                        continue;
                    265:                bp++;
                    266:                return (tdecode(bp, area));
                    267:        }
                    268: }
                    269: 
                    270: /*
                    271:  * Tdecode does the grung work to decode the
                    272:  * string capability escapes.
                    273:  */
                    274: static char *
                    275: tdecode(str, area)
                    276:        register char *str;
                    277:        char **area;
                    278: {
                    279:        register char *cp;
                    280:        register int c;
                    281:        int i;
                    282: 
                    283:        cp = *area;
                    284:        while (c = *str++) {
                    285:            if (c == ':' && *(cp-1) != '\\')
                    286:                break;
                    287:            *cp++ = c;
                    288:        }
                    289:        *cp++ = 0;
                    290:        str = *area;
                    291:        *area = cp;
                    292:        return (str);
                    293: }

unix.superglobalmegacorp.com

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.