Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <fcall.h>
#include <thread.h>
#include <9p.h>

/*
 * Generous estimate of number of fields, including terminal nil pointer
 */
static int
ncmdfield(char *p, int n)
{
        int white, nwhite;
        char *ep;
        int nf;

        if(p == nil)
                return 1;

        nf = 0;
        ep = p+n;
        white = 1;      /* first text will start field */
        while(p < ep){
                nwhite = (strchr(" \t\r\n", *p++ & 0xFF) != 0); /* UTF is irrelevant */
                if(white && !nwhite)    /* beginning of field */
                        nf++;
                white = nwhite;
        }
        return nf+1;    /* +1 for nil */
}

/*
 *  parse a command written to a device
 */
Cmdbuf*
parsecmd(char *p, int n)
{
        Cmdbuf *cb;
        int nf;
        char *sp;

        nf = ncmdfield(p, n);

        /* allocate Cmdbuf plus string pointers plus copy of string including \0 */
        sp = emalloc9p(sizeof(*cb) + nf * sizeof(char*) + n + 1);
        cb = (Cmdbuf*)sp;
        cb->f = (char**)(&cb[1]);
        cb->buf = (char*)(&cb->f[nf]);

        memmove(cb->buf, p, n);

        /* dump new line and null terminate */
        if(n > 0 && cb->buf[n-1] == '\n')
                n--;
        cb->buf[n] = '\0';

        cb->nf = tokenize(cb->buf, cb->f, nf-1);
        cb->f[cb->nf] = nil;

        return cb;
}

/*
 * Reconstruct original message, for error diagnostic
 */
void
respondcmderror(Req *r, Cmdbuf *cb, char *fmt, ...)
{
        int i;
        va_list arg;
        char *p, *e;
        char err[ERRMAX];
        
        e = err+ERRMAX-10;
        va_start(arg, fmt);
        p = vseprint(err, e, fmt, arg);
        va_end(arg);
        p = seprint(p, e, ": \"");
        quotefmtinstall();      /* just in case */
        for(i=0; i<cb->nf; i++){
                if(i > 0)
                        p = seprint(p, e, " ");
                p = seprint(p, e, "%q", cb->f[i]);
        }
        strcpy(p, "\"");
        respond(r, err);
}

/*
 * Look up entry in table
 */
Cmdtab*
lookupcmd(Cmdbuf *cb, Cmdtab *ctab, int nctab)
{
        int i;
        Cmdtab *ct;

        if(cb->nf == 0){
                werrstr("empty control message");
                return nil;
        }

        for(ct = ctab, i=0; i<nctab; i++, ct++){
                if(strcmp(ct->cmd, "*") !=0)    /* wildcard always matches */
                if(strcmp(ct->cmd, cb->f[0]) != 0)
                        continue;
                if(ct->narg != 0 && ct->narg != cb->nf){
                        werrstr("bad # args to command");
                        return nil;
                }
                return ct;
        }

        werrstr("unknown control message");
        return nil;
}