reg.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include "eqn.h"
   5
   6 #define NREGS           2048
   7 #define EPREFIX         ""
   8
   9 static int sreg_max;            /* maximum allocated string register */
  10 static int sreg_free[NREGS];    /* free string registers */
  11 static int sreg_n;              /* number of items in sreg_free[] */
  12 static char sreg_name[NREGS][RLEN];
  13 static char sreg_read[NREGS][RLEN];
  14
  15 static int nreg_max;
  16 static int nreg_free[NREGS];
  17 static int nreg_n;
  18 static char nreg_name[NREGS][RLEN];
  19 static char nreg_read[NREGS][RLEN];
  20
  21 /* allocate a troff string register */
  22 int sregmk(void)
  23 {
  24         int id = sreg_n ? sreg_free[--sreg_n] : ++sreg_max;
  25         sprintf(sreg_name[id], "%s%02d", EPREFIX, id);
  26         sprintf(sreg_read[id], "\\*%s", escarg(sreg_name[id]));
  27         return id;
  28 }
  29
  30 /* free a troff string register */
  31 void sregrm(int id)
  32 {
  33         sreg_free[sreg_n++] = id;
  34 }
  35
  36 char *sregname(int id)
  37 {
  38         return sreg_name[id];
  39 }
  40
  41 char *sreg(int id)
  42 {
  43         return sreg_read[id];
  44 }
  45
  46 /* allocate a troff number register */
  47 int nregmk(void)
  48 {
  49         int id = nreg_n ? nreg_free[--nreg_n] : ++nreg_max;
  50         sprintf(nreg_name[id], "%s%02d", EPREFIX, id);
  51         sprintf(nreg_read[id], "\\n%s", escarg(nreg_name[id]));
  52         return id;
  53 }
  54
  55 /* free a troff number register */
  56 void nregrm(int id)
  57 {
  58         nreg_free[nreg_n++] = id;
  59 }
  60
  61 char *nregname(int id)
  62 {
  63         return nreg_name[id];
  64 }
  65
  66 char *nreg(int id)
  67 {
  68         return nreg_read[id];
  69 }
  70
  71 /* free all allocated registers */
  72 void reg_reset(void)
  73 {
  74         nreg_max = 0;
  75         nreg_n = 0;
  76         sreg_max = 11;
  77         sreg_n = 0;
  78 }
  79
  80 /* format the argument of a troff escape like \s or \f */
  81 char *escarg(char *arg)
  82 {
  83         static char buf[256];
  84         if (!arg[1])
  85                 sprintf(buf, "%c", arg[0]);
  86         else if (!arg[2])
  87                 sprintf(buf, "(%c%c", arg[0], arg[1]);
  88         else
  89                 sprintf(buf, "[%s]", arg);
  90         return buf;
  91 }