1 #include "u.h" 2 #include "../port/lib.h" 3 #include "mem.h" 4 #include "dat.h" 5 #include "fns.h" 6 #include "../port/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 } 115