sys/src/cmd/db/input.c

   1 /*
   2  *
   3  *      debugger
   4  *
   5  */
   6
   7 #include "defs.h"
   8 #include "fns.h"
   9
  10 Rune    line[LINSIZ];
  11 extern  int     infile;
  12 Rune    *lp;
  13 int     peekc,lastc = EOR;
  14 int     eof;
  15
  16 /* input routines */
  17
  18 eol(int c)
  19 {
  20         return(c==EOR || c==';');
  21 }
  22
  23 int
  24 rdc(void)
  25 {
  26         do {
  27                 readchar();
  28         } while (lastc==SPC || lastc==TB);
  29         return(lastc);
  30 }
  31
  32 void
  33 reread(void)
  34 {
  35         peekc = lastc;
  36 }
  37
  38 void
  39 clrinp(void)
  40 {
  41         flush();
  42         lp = 0;
  43         peekc = 0;
  44 }
  45
  46 int
  47 readrune(int fd, Rune *r)
  48 {
  49         char buf[UTFmax];
  50         int i;
  51
  52         for(i=0; i<UTFmax && !fullrune(buf, i); i++)
  53                 if(read(fd, buf+i, 1) <= 0)
  54                         return -1;
  55         chartorune(r, buf);
  56         return 1;
  57 }
  58
  59 int
  60 readchar(void)
  61 {
  62         Rune *p;
  63
  64         if (eof)
  65                 lastc=0;
  66         else if (peekc) {
  67                 lastc = peekc;
  68                 peekc = 0;
  69         }
  70         else {
  71                 if (lp==0) {
  72                         for (p = line; p < &line[LINSIZ-1]; p++) {
  73                                 eof = readrune(infile, p) <= 0;
  74                                 if (mkfault) {
  75                                         eof = 0;
  76                                         error(0);
  77                                 }
  78                                 if (eof) {
  79                                         p--;
  80                                         break;
  81                                 }
  82                                 if (*p == EOR) {
  83                                         if (p <= line)
  84                                                 break;
  85                                         if (p[-1] != '\\')
  86                                                 break;
  87                                         p -= 2;
  88                                 }
  89                         }
  90                         p[1] = 0;
  91                         lp = line;
  92                 }
  93                 if ((lastc = *lp) != 0)
  94                         lp++;
  95         }
  96         return(lastc);
  97 }
  98
  99 nextchar(void)
 100 {
 101         if (eol(rdc())) {
 102                 reread();
 103                 return(0);
 104         }
 105         return(lastc);
 106 }
 107
 108 quotchar(void)
 109 {
 110         if (readchar()=='\\')
 111                 return(readchar());
 112         else if (lastc=='\'')
 113                 return(0);
 114         else
 115                 return(lastc);
 116 }
 117
 118 void
 119 getformat(char *deformat)
 120 {
 121         char *fptr;
 122         BOOL    quote;
 123         Rune r;
 124
 125         fptr=deformat;
 126         quote=FALSE;
 127         while ((quote ? readchar()!=EOR : !eol(readchar()))){
 128                 r = lastc;
 129                 fptr += runetochar(fptr, &r);
 130                 if (lastc == '"')
 131                         quote = ~quote;
 132         }
 133         lp--;
 134         if (fptr!=deformat)
 135                 *fptr = '\0';
 136 }
 137
 138 /*
 139  *      check if the input line if of the form:
 140  *              <filename>:<digits><verb> ...
 141  *
 142  *      we handle this case specially because we have to look ahead
 143  *      at the token after the colon to decide if it is a file reference
 144  *      or a colon-command with a symbol name prefix.
 145  */
 146
 147 int
 148 isfileref(void)
 149 {
 150         Rune *cp;
 151
 152         for (cp = lp-1; *cp && !strchr(CMD_VERBS, *cp); cp++)
 153                 if (*cp == '\\' && cp[1])       /* escape next char */
 154                         cp++;
 155         if (*cp && cp > lp-1) {
 156                 while (*cp == ' ' || *cp == '\t')
 157                         cp++;
 158                 if (*cp++ == ':') {
 159                         while (*cp == ' ' || *cp == '\t')
 160                                 cp++;
 161                         if (isdigit(*cp))
 162                                 return 1;
 163                 }
 164         }
 165         return 0;
 166 }