ref: b66f7af07003a601e2e125e2c2926586c8664571
dir: neatroff/cp.c
/* copy-mode character interpretation */
#include <u.h>
#include <libc.h>
#include <stdio.h>
#include "roff.h"
static int cp_blkdep; /* input block depth (text in \{ and \}) */
static int cp_cpmode; /* disable the interpretation of \w and \E */
static int cp_reqdep; /* the block depth of current request line */
/* just like cp_next(), but remove c_ni characters */
static int cp_noninext(void)
{
int c = cp_next();
while (c == c_ni)
c = cp_next();
return c;
}
/* return 1 if \*[] includes a space */
static int cparg(char *d, int len)
{
int c = cp_noninext();
int i = 0;
if (c == '(') {
i += utf8next(d + i, cp_noninext);
i += utf8next(d + i, cp_noninext);
} else if (!n_cp && c == '[') {
c = cp_noninext();
while (c >= 0 && c != ']' && c != ' ') {
if (i + 1 < len)
d[i++] = c;
c = cp_noninext();
}
d[i] = '\0';
return c == ' ';
} else {
cp_back(c);
utf8next(d, cp_noninext);
}
return 0;
}
static int regid(void)
{
char regname[NMLEN];
cparg(regname, sizeof(regname));
return map(regname);
}
/* interpolate \n(xy */
static void cp_num(void)
{
int id;
int c = cp_noninext();
char *s;
if (c != '-' && c != '+')
cp_back(c);
id = regid();
if (c == '-' || c == '+')
num_inc(id, c == '+');
if ((s = num_str(id)) != NULL)
in_push(s, NULL);
}
/* interpolate \*(xy */
static void cp_str(void)
{
char reg[NMLEN];
char *args[NARGS + 2] = {reg};
char *buf = NULL;
if (cparg(reg, sizeof(reg))) {
buf = tr_args(args + 1, ']', cp_noninext, cp_back);
cp_noninext();
}
if (str_get(map(reg)))
in_push(str_get(map(reg)), buf ? args : NULL);
else if (!n_cp)
tr_req(map(reg), args);
free(buf);
}
/* interpolate \g(xy */
static void cp_numfmt(void)
{
in_push(num_getfmt(regid()), NULL);
}
/* interpolate \$*, \$@, and \$^ */
static void cp_args(int quote, int escape)
{
struct sbuf sb;
char *s;
int i;
sbuf_init(&sb);
for (i = 1; i < in_nargs(); i++) {
sbuf_append(&sb, i > 1 ? " " : "");
sbuf_append(&sb, quote ? "\"" : "");
s = in_arg(i);
while (*s) {
sbuf_append(&sb, escape && *s == '"' ? "\"" : "");
sbuf_add(&sb, (unsigned char) *s++);
}
sbuf_append(&sb, quote ? "\"" : "");
}
in_push(sbuf_buf(&sb), NULL);
sbuf_done(&sb);
}
/* interpolate \$1 */
static void cp_arg(void)
{
char argname[NMLEN];
char *arg = NULL;
int argnum;
cparg(argname, sizeof(argname));
if (!strcmp("@", argname)) {
cp_args(1, 0);
return;
}
if (!strcmp("*", argname)) {
cp_args(0, 0);
return;
}
if (!strcmp("^", argname)) {
cp_args(1, 1);
return;
}
argnum = atoi(argname);
if (argnum >= 0 && argnum < NARGS)
arg = in_arg(argnum);
if (arg)
in_push(arg, NULL);
}
/* interpolate \w'xyz' */
static void cp_width(void)
{
char wid[16];
sprintf(wid, "%d", ren_wid(cp_next, cp_back));
in_push(wid, NULL);
}
/* define a register as \R'xyz expr' */
static void cp_numdef(void)
{
char *arg = quotednext(cp_noninext, cp_back);
char *s = arg;
while (*s && *s != ' ')
s++;
if (!*s) {
free(arg);
return;
}
*s++ = '\0';
num_set(map(arg), eval_re(s, num_get(map(arg)), 'u'));
free(arg);
}
/* conditional interpolation as \?'cond@expr1@expr2@' */
static void cp_cond(void)
{
char delim[GNLEN], cs[GNLEN];
char *r, *s;
char *s1, *s2;
int n;
char *arg = quotednext(cp_noninext, cp_back);
s = arg;
n = eval_up(&s, '\0');
if (charread(&s, delim) < 0) {
free(arg);
return;
}
if (!strcmp(delim, "\\&") && charread(&s, delim) < 0) {
free(arg);
return;
}
s1 = s;
r = s;
while (charread_delim(&s, cs, delim) >= 0)
r = s;
*r = '\0';
s2 = s;
r = s;
while (charread_delim(&s, cs, delim) >= 0)
r = s;
*r = '\0';
in_push(n > 0 ? s1 : s2, NULL);
free(arg);
}
static int cp_raw(void)
{
int c;
if (in_top() >= 0)
return in_next();
do {
c = in_next();
} while (c == c_ni);
if (c == c_ec) {
do {
c = in_next();
} while (c == c_ni);
if (c == '\n')
return cp_raw();
if (c == '.')
return '.';
if (c == '\\') {
in_back('\\');
return c_ni;
}
if (c == 't') {
in_back('\t');
return c_ni;
}
if (c == 'a') {
in_back('');
return c_ni;
}
/* replace \{ and \} with a space if not in copy mode */
if (c == '}' && !cp_cpmode) {
cp_blkdep--;
return ' ';
}
if (c == '{' && !cp_cpmode) {
cp_blkdep++;
return ' ';
}
in_back(c);
return c_ec;
}
return c;
}
int cp_next(void)
{
int c;
if (in_top() >= 0)
return in_next();
c = cp_raw();
if (c == c_ec) {
c = cp_raw();
if (c == 'E' && !cp_cpmode)
c = cp_next();
if (c == '"') {
while (c >= 0 && c != '\n')
c = cp_raw();
} else if (c == 'w' && !cp_cpmode) {
cp_width();
c = cp_next();
} else if (c == 'n') {
cp_num();
c = cp_next();
} else if (c == '*') {
cp_str();
c = cp_next();
} else if (c == 'g') {
cp_numfmt();
c = cp_next();
} else if (c == '$') {
cp_arg();
c = cp_next();
} else if (c == '?') {
cp_cond();
c = cp_next();
} else if (c == 'R' && !cp_cpmode) {
cp_numdef();
c = cp_next();
} else {
cp_back(c);
c = c_ec;
}
}
return c;
}
void cp_blk(int skip)
{
if (skip) {
int c = cp_raw();
while (c >= 0 && (c != '\n' || cp_blkdep > cp_reqdep))
c = cp_raw();
} else {
int c = cp_next();
while (c == ' ')
c = cp_next();
/* push back if the space is not inserted due to \{ and \} */
if (c != ' ')
cp_back(c);
}
}
void cp_copymode(int mode)
{
cp_cpmode = mode;
}
/* beginning of a request; save current cp_blkdep */
void cp_reqbeg(void)
{
cp_reqdep = cp_blkdep;
}