BSD 4 release

[unix-history] / usr / src / cmd / sdb / decode.c

static  char sccsid[] = "@(#)decode.c 4.1 10/9/80";
#include "head.h"

/* decode() - read a line from standard input and decode it */

decode(p)
char *p; {
       register char c, *q;
       register int diff;
       integ = scallf = reflag = colonflag = ncolonflag = percentflag = 0;
       proc[0] = cmd = args[0] = var[0] = '\0';
       argsp = args;
       
       if (eqany(*p, "/?")) {  /* regular expression */
               c = *p;
               redir = (c == '/');
               reflag = 1;
               p++;
               if (*p == '\n' || *p == c) return(0);
               q = re;
               while(*p != c && *p != '\n') *q++ = *p++;
               *q = '\0';
               return(0);
       }
       
       if (*p == '!') { /* shell escape */
               for (q = p; *q != '\n'; q++) ;
               *q = '\0';
               system(p+1);
               return(0);
       }
       
       if (*p == '\n') {
               cmd = '\n';
               return(0);
       }
       
       if (*p == ':') {
               colonflag++;
       }
       
       while (*p != '\n') {    /* decode item by item */
       
               if (number(*p)) {       /* decimal number */
                       if (integ) {
                               error("Too many numbers");
                               return(1);
                       }
                       integ = readint(&p);
                       if (*p == ':') {
                               ncolonflag++;
                               p++;
                       }
                       continue;
               }
               
               if (varchar(*p) || eqany(*p, COMMANDS)) { 
                                       /* proc, variable or command */
                       if (cmd != '\0') {
                               p = cpall(args, p);
                               continue;
                       }
                       q = p;
                       while (varchar(*q) || number(*q) || eqany(*q,COMMANDS))
                               q++;
                       if (*q == '(') {        /* procedure call */
                               if (proc[0] != '\0') {
                                       error("Too many procedure calls");
                                       return(1);
                               }
                               scallf = 1;
                               p = cpname(proc, p);
                               p = cpall(args, p);
                               continue;
                       }
                       if (*q == ':') {        /* procedure name */
                               colonflag++;
                               p = cpname(proc, p);
                               continue;
                       }
                       if (*q == '$') {        /* variable name */
                               p = cpname(var, p);
                               continue;
                       }
                       if (((q-p == 1 && eqany(*p,COMMANDS) && 
                               (proc[0]=='\0' || eqany(*p, "abcd"))) ||
                               (integ && eqany(*p,COMMANDS)) || 
                                eqany(*p, "+-?")) 
                               && !(*p=='-' && *(p+1) == '>'))
                                                       {  /* command */
                               cmd = *p++;
                               if (eqany(cmd, "Macers")) {
                                       while(*p == ' ')
                                               p++;
                                       p = cpall(args, p);
                               }
                               continue;
                       }
                       /* otherwise, its a variable */
                       if (var[0] != '\0') {
                               error("Too many variable names");
                               return(1);
                       }
                       p = cpname(var, p);
                       if (*p == '%') {
                               percentflag++;
                               p++;
                       }
                       if (eqstr(var, ".?")) {
                               var[1] = '\0';
                               cmd = '?';
                       }
                       if (*p == '\n') {
                               cmd = '/';
                               continue;
                       }
                       if (cmd == '\0') cmd = *p ? *p : '/';
                       p++;
                       p = cpall(args,p);
                       continue;
               }
               p++;    /* otherwise ignore p */
       }
       return(0);
}