vx32

Local 9vx git repository for patches.
git clone git://r-36.net/vx32
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parse.c (2010B)


      1 #include	"u.h"
      2 #include	"lib.h"
      3 #include	"mem.h"
      4 #include	"dat.h"
      5 #include	"fns.h"
      6 #include	"error.h"
      7 
      8 /*
      9  * Generous estimate of number of fields, including terminal nil pointer
     10  */
     11 static int
     12 ncmdfield(char *p, int n)
     13 {
     14 	int white, nwhite;
     15 	char *ep;
     16 	int nf;
     17 
     18 	if(p == nil)
     19 		return 1;
     20 
     21 	nf = 0;
     22 	ep = p+n;
     23 	white = 1;	/* first text will start field */
     24 	while(p < ep){
     25 		nwhite = (strchr(" \t\r\n", *p++ & 0xFF) != 0);	/* UTF is irrelevant */
     26 		if(white && !nwhite)	/* beginning of field */
     27 			nf++;
     28 		white = nwhite;
     29 	}
     30 	return nf+1;	/* +1 for nil */
     31 }
     32 
     33 /*
     34  *  parse a command written to a device
     35  */
     36 Cmdbuf*
     37 parsecmd(char *p, int n)
     38 {
     39 	Cmdbuf *volatile cb;
     40 	int nf;
     41 	char *sp;
     42 
     43 	nf = ncmdfield(p, n);
     44 
     45 	/* allocate Cmdbuf plus string pointers plus copy of string including \0 */
     46 	sp = smalloc(sizeof(*cb) + nf * sizeof(char*) + n + 1);
     47 	cb = (Cmdbuf*)sp;
     48 	cb->f = (char**)(&cb[1]);
     49 	cb->buf = (char*)(&cb->f[nf]);
     50 
     51 	if(up!=nil && waserror()){
     52 		free(cb);
     53 		nexterror();
     54 	}
     55 	memmove(cb->buf, p, n);
     56 	if(up != nil)
     57 		poperror();
     58 
     59 	/* dump new line and null terminate */
     60 	if(n > 0 && cb->buf[n-1] == '\n')
     61 		n--;
     62 	cb->buf[n] = '\0';
     63 
     64 	cb->nf = tokenize(cb->buf, cb->f, nf-1);
     65 	cb->f[cb->nf] = nil;
     66 
     67 	return cb;
     68 }
     69 
     70 /*
     71  * Reconstruct original message, for error diagnostic
     72  */
     73 void
     74 cmderror(Cmdbuf *cb, char *s)
     75 {
     76 	int i;
     77 	char *p, *e;
     78 
     79 	p = up->genbuf;
     80 	e = p+ERRMAX-10;
     81 	p = seprint(p, e, "%s \"", s);
     82 	for(i=0; i<cb->nf; i++){
     83 		if(i > 0)
     84 			p = seprint(p, e, " ");
     85 		p = seprint(p, e, "%q", cb->f[i]);
     86 	}
     87 	strcpy(p, "\"");
     88 	error(up->genbuf);
     89 }
     90 
     91 /*
     92  * Look up entry in table
     93  */
     94 Cmdtab*
     95 lookupcmd(Cmdbuf *cb, Cmdtab *ctab, int nctab)
     96 {
     97 	int i;
     98 	Cmdtab *ct;
     99 
    100 	if(cb->nf == 0)
    101 		error("empty control message");
    102 
    103 	for(ct = ctab, i=0; i<nctab; i++, ct++){
    104 		if(strcmp(ct->cmd, "*") !=0)	/* wildcard always matches */
    105 		if(strcmp(ct->cmd, cb->f[0]) != 0)
    106 			continue;
    107 		if(ct->narg != 0 && ct->narg != cb->nf)
    108 			cmderror(cb, Ecmdargs);
    109 		return ct;
    110 	}
    111 
    112 	cmderror(cb, "unknown control message");
    113 	return nil;
    114 }