114 lines
1.9 KiB
C
114 lines
1.9 KiB
C
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#include "u.h"
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#include "lib.h"
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#include "dat.h"
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#include "fns.h"
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#include "error.h"
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/*
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* Generous estimate of number of fields, including terminal nil pointer
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*/
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static int
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ncmdfield(char *p, int n)
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{
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int white, nwhite;
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char *ep;
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int nf;
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if(p == nil)
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return 1;
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nf = 0;
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ep = p+n;
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white = 1; /* first text will start field */
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while(p < ep){
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nwhite = (strchr(" \t\r\n", *p++ & 0xFF) != 0); /* UTF is irrelevant */
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if(white && !nwhite) /* beginning of field */
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nf++;
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white = nwhite;
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}
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return nf+1; /* +1 for nil */
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}
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/*
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* parse a command written to a device
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*/
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Cmdbuf*
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parsecmd(char *p, int n)
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{
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Cmdbuf *volatile cb;
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int nf;
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char *sp;
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nf = ncmdfield(p, n);
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/* allocate Cmdbuf plus string pointers plus copy of string including \0 */
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sp = smalloc(sizeof(*cb) + nf * sizeof(char*) + n + 1);
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cb = (Cmdbuf*)sp;
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cb->f = (char**)(&cb[1]);
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cb->buf = (char*)(&cb->f[nf]);
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if(up!=nil && waserror()){
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free(cb);
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nexterror();
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}
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memmove(cb->buf, p, n);
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if(up != nil)
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poperror();
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/* dump new line and null terminate */
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if(n > 0 && cb->buf[n-1] == '\n')
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n--;
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cb->buf[n] = '\0';
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cb->nf = tokenize(cb->buf, cb->f, nf-1);
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cb->f[cb->nf] = nil;
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return cb;
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}
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/*
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* Reconstruct original message, for error diagnostic
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*/
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void
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cmderror(Cmdbuf *cb, char *s)
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{
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int i;
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char *p, *e;
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p = up->genbuf;
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e = p+ERRMAX-10;
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p = seprint(p, e, "%s \"", s);
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for(i=0; i<cb->nf; i++){
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if(i > 0)
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p = seprint(p, e, " ");
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p = seprint(p, e, "%q", cb->f[i]);
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}
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strcpy(p, "\"");
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error(up->genbuf);
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}
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/*
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* Look up entry in table
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*/
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Cmdtab*
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lookupcmd(Cmdbuf *cb, Cmdtab *ctab, int nctab)
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{
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int i;
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Cmdtab *ct;
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if(cb->nf == 0)
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error("empty control message");
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for(ct = ctab, i=0; i<nctab; i++, ct++){
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if(strcmp(ct->cmd, "*") !=0) /* wildcard always matches */
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if(strcmp(ct->cmd, cb->f[0]) != 0)
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continue;
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if(ct->narg != 0 && ct->narg != cb->nf)
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cmderror(cb, Ecmdargs);
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return ct;
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}
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cmderror(cb, "unknown control message");
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return nil;
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}
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