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