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mksh/lex.c

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/* $OpenBSD: lex.c,v 1.39 2006/04/10 14:38:59 jaredy Exp $ */
#include "sh.h"
__RCSID("$MirOS: src/bin/mksh/lex.c,v 1.12 2006/05/10 18:54:11 tg Exp $");
/* Structure to keep track of the lexing state and the various pieces of info
* needed for each particular state. */
typedef struct lex_state Lex_state;
struct lex_state {
int ls_state;
union {
/* $(...) */
struct scsparen_info {
int nparen; /* count open parenthesis */
int csstate; /* XXX remove */
#define ls_scsparen ls_info.u_scsparen
} u_scsparen;
/* $((...)) */
struct sasparen_info {
int nparen; /* count open parenthesis */
int start; /* marks start of $(( in output str */
#define ls_sasparen ls_info.u_sasparen
} u_sasparen;
/* ((...)) */
struct sletparen_info {
int nparen; /* count open parenthesis */
#define ls_sletparen ls_info.u_sletparen
} u_sletparen;
/* `...` */
struct sbquote_info {
int indquotes; /* true if in double quotes: "`...`" */
#define ls_sbquote ls_info.u_sbquote
} u_sbquote;
Lex_state *base; /* used to point to next state block */
} ls_info;
};
typedef struct State_info State_info;
struct State_info {
Lex_state *base;
Lex_state *end;
};
static void readhere(struct ioword *);
static int getsc__(void);
static void getsc_line(Source *);
static int getsc_bn(void);
static char *get_brace_var(XString *, char *);
static int arraysub(char **);
static const char *ungetsc(int);
static void gethere(void);
static Lex_state *push_state_(State_info *, Lex_state *);
static Lex_state *pop_state_(State_info *, Lex_state *);
static int backslash_skip;
static int ignore_backslash_newline;
/* optimized getsc_bn() */
#define getsc() (*source->str != '\0' && *source->str != '\\' \
&& !backslash_skip ? *source->str++ : getsc_bn())
/* optimized getsc__() */
#define getsc_() ((*source->str != '\0') ? *source->str++ : getsc__())
#define STATE_BSIZE 32
#define PUSH_STATE(s) do { \
if (++statep == state_info.end) \
statep = push_state_(&state_info, statep); \
state = statep->ls_state = (s); \
} while (0)
#define POP_STATE() do { \
if (--statep == state_info.base) \
statep = pop_state_(&state_info, statep); \
state = statep->ls_state; \
} while (0)
/*
* Lexical analyzer
*
* tokens are not regular expressions, they are LL(1).
* for example, "${var:-${PWD}}", and "$(size $(whence ksh))".
* hence the state stack.
*/
int
yylex(int cf)
{
Lex_state states[STATE_BSIZE], *statep, *s2, *base;
State_info state_info;
int c, state;
XString ws; /* expandable output word */
char *wp; /* output word pointer */
char *sp, *dp;
int c2;
Again:
states[0].ls_state = -1;
states[0].ls_info.base = NULL;
statep = &states[1];
state_info.base = states;
state_info.end = &states[STATE_BSIZE];
Xinit(ws, wp, 64, ATEMP);
backslash_skip = 0;
ignore_backslash_newline = 0;
if (cf&ONEWORD)
state = SWORD;
else if (cf&LETEXPR) {
*wp++ = OQUOTE; /* enclose arguments in (double) quotes */
state = SLETPAREN;
statep->ls_sletparen.nparen = 0;
} else { /* normal lexing */
state = (cf & HEREDELIM) ? SHEREDELIM : SBASE;
while ((c = getsc()) == ' ' || c == '\t')
;
if (c == '#') {
ignore_backslash_newline++;
while ((c = getsc()) != '\0' && c != '\n')
;
ignore_backslash_newline--;
}
ungetsc(c);
}
if (source->flags & SF_ALIAS) { /* trailing ' ' in alias definition */
source->flags &= ~SF_ALIAS;
cf |= ALIAS;
}
/* Initial state: one of SBASE SHEREDELIM SWORD SASPAREN */
statep->ls_state = state;
/* collect non-special or quoted characters to form word */
while (!((c = getsc()) == 0 ||
((state == SBASE || state == SHEREDELIM) && ctype(c, C_LEX1)))) {
Xcheck(ws, wp);
switch (state) {
case SBASE:
if (c == '[' && (cf & (VARASN|ARRAYVAR))) {
*wp = EOS; /* temporary */
if (is_wdvarname(Xstring(ws, wp), false)) {
char *p, *tmp;
if (arraysub(&tmp)) {
*wp++ = CHAR;
*wp++ = c;
for (p = tmp; *p; ) {
Xcheck(ws, wp);
*wp++ = CHAR;
*wp++ = *p++;
}
afree(tmp, ATEMP);
break;
} else {
Source *s;
s = pushs(SREREAD,
source->areap);
s->start = s->str
= s->u.freeme = tmp;
s->next = source;
source = s;
}
}
*wp++ = CHAR;
*wp++ = c;
break;
}
/* FALLTHRU */
Sbase1: /* includes *(...|...) pattern (*+?@!) */
if (c == '*' || c == '@' || c == '+' || c == '?' ||
c == '!') {
c2 = getsc();
if (c2 == '(' /*)*/ ) {
*wp++ = OPAT;
*wp++ = c;
PUSH_STATE(SPATTERN);
break;
}
ungetsc(c2);
}
/* FALLTHRU */
Sbase2: /* doesn't include *(...|...) pattern (*+?@!) */
switch (c) {
case '\\':
c = getsc();
if (c) /* trailing \ is lost */
*wp++ = QCHAR, *wp++ = c;
break;
case '\'':
*wp++ = OQUOTE;
ignore_backslash_newline++;
PUSH_STATE(SSQUOTE);
break;
case '"':
*wp++ = OQUOTE;
PUSH_STATE(SDQUOTE);
break;
default:
goto Subst;
}
break;
Subst:
switch (c) {
case '\\':
c = getsc();
switch (c) {
case '"':
if ((cf & HEREDOC))
goto heredocquote;
/* FALLTROUGH */
case '\\':
case '$': case '`':
*wp++ = QCHAR, *wp++ = c;
break;
default:
heredocquote:
Xcheck(ws, wp);
if (c) { /* trailing \ is lost */
*wp++ = CHAR, *wp++ = '\\';
*wp++ = CHAR, *wp++ = c;
}
break;
}
break;
case '$':
c = getsc();
if (c == '(') /*)*/ {
c = getsc();
if (c == '(') /*)*/ {
PUSH_STATE(SASPAREN);
statep->ls_sasparen.nparen = 2;
statep->ls_sasparen.start =
Xsavepos(ws, wp);
*wp++ = EXPRSUB;
} else {
ungetsc(c);
PUSH_STATE(SCSPAREN);
statep->ls_scsparen.nparen = 1;
statep->ls_scsparen.csstate = 0;
*wp++ = COMSUB;
}
} else if (c == '{') /*}*/ {
*wp++ = OSUBST;
*wp++ = '{'; /*}*/
wp = get_brace_var(&ws, wp);
c = getsc();
/* allow :# and :% (ksh88 compat) */
if (c == ':') {
*wp++ = CHAR, *wp++ = c;
c = getsc();
}
/* If this is a trim operation,
* treat (,|,) specially in STBRACE.
*/
if (c == '#' || c == '%') {
ungetsc(c);
PUSH_STATE(STBRACE);
} else {
ungetsc(c);
PUSH_STATE(SBRACE);
}
} else if (ctype(c, C_ALPHA)) {
*wp++ = OSUBST;
*wp++ = 'X';
do {
Xcheck(ws, wp);
*wp++ = c;
c = getsc();
} while (ctype(c, C_ALPHA|C_DIGIT));
*wp++ = '\0';
*wp++ = CSUBST;
*wp++ = 'X';
ungetsc(c);
} else if (ctype(c, C_DIGIT|C_VAR1)) {
Xcheck(ws, wp);
*wp++ = OSUBST;
*wp++ = 'X';
*wp++ = c;
*wp++ = '\0';
*wp++ = CSUBST;
*wp++ = 'X';
} else {
*wp++ = CHAR, *wp++ = '$';
ungetsc(c);
}
break;
case '`':
PUSH_STATE(SBQUOTE);
*wp++ = COMSUB;
/* Need to know if we are inside double quotes
* since sh/at&t-ksh translate the \" to " in
* "`..\"..`".
* This is not done in posix mode (section
* 3.2.3, Double Quotes: "The backquote shall
* retain its special meaning introducing the
* other form of command substitution (see
* 3.6.3). The portion of the quoted string
* from the initial backquote and the
* characters up to the next backquote that
* is not preceded by a backslash (having
* escape characters removed) defines that
* command whose output replaces `...` when
* the word is expanded."
* Section 3.6.3, Command Substitution:
* "Within the backquoted style of command
* substitution, backslash shall retain its
* literal meaning, except when followed by
* $ ` \.").
*/
statep->ls_sbquote.indquotes = 0;
s2 = statep;
base = state_info.base;
while (1) {
for (; s2 != base; s2--) {
if (s2->ls_state == SDQUOTE) {
statep->ls_sbquote.indquotes = 1;
break;
}
}
if (s2 != base)
break;
if (!(s2 = s2->ls_info.base))
break;
base = s2-- - STATE_BSIZE;
}
break;
case QCHAR:
if (cf & LQCHAR) {
*wp++ = QCHAR;
*wp++ = getsc();
break;
}
/* FALLTHRU */
default:
*wp++ = CHAR, *wp++ = c;
}
break;
case SSQUOTE:
if (c == '\'') {
POP_STATE();
*wp++ = CQUOTE;
ignore_backslash_newline--;
} else
*wp++ = QCHAR, *wp++ = c;
break;
case SDQUOTE:
if (c == '"') {
POP_STATE();
*wp++ = CQUOTE;
} else
goto Subst;
break;
case SCSPAREN: /* $( .. ) */
/* todo: deal with $(...) quoting properly
* kludge to partly fake quoting inside $(..): doesn't
* really work because nested $(..) or ${..} inside
* double quotes aren't dealt with.
*/
switch (statep->ls_scsparen.csstate) {
case 0: /* normal */
switch (c) {
case '(':
statep->ls_scsparen.nparen++;
break;
case ')':
statep->ls_scsparen.nparen--;
break;
case '\\':
statep->ls_scsparen.csstate = 1;
break;
case '"':
statep->ls_scsparen.csstate = 2;
break;
case '\'':
statep->ls_scsparen.csstate = 4;
ignore_backslash_newline++;
break;
}
break;
case 1: /* backslash in normal mode */
case 3: /* backslash in double quotes */
--statep->ls_scsparen.csstate;
break;
case 2: /* double quotes */
if (c == '"')
statep->ls_scsparen.csstate = 0;
else if (c == '\\')
statep->ls_scsparen.csstate = 3;
break;
case 4: /* single quotes */
if (c == '\'') {
statep->ls_scsparen.csstate = 0;
ignore_backslash_newline--;
}
break;
}
if (statep->ls_scsparen.nparen == 0) {
POP_STATE();
*wp++ = 0; /* end of COMSUB */
} else
*wp++ = c;
break;
case SASPAREN: /* $(( .. )) */
/* todo: deal with $((...); (...)) properly */
/* XXX should nest using existing state machine
* (embed "..", $(...), etc.) */
if (c == '(')
statep->ls_sasparen.nparen++;
else if (c == ')') {
statep->ls_sasparen.nparen--;
if (statep->ls_sasparen.nparen == 1) {
/*(*/
if ((c2 = getsc()) == ')') {
POP_STATE();
*wp++ = 0; /* end of EXPRSUB */
break;
} else {
char *s;
ungetsc(c2);
/* mismatched parenthesis -
* assume we were really
* parsing a $(..) expression
*/
s = Xrestpos(ws, wp,
statep->ls_sasparen.start);
memmove(s + 1, s, wp - s);
*s++ = COMSUB;
*s = '('; /*)*/
wp++;
statep->ls_scsparen.nparen = 1;
statep->ls_scsparen.csstate = 0;
state = statep->ls_state =
SCSPAREN;
}
}
}
*wp++ = c;
break;
case SBRACE:
/*{*/
if (c == '}') {
POP_STATE();
*wp++ = CSUBST;
*wp++ = /*{*/ '}';
} else
goto Sbase1;
break;
case STBRACE:
/* Same as SBRACE, except (,|,) treated specially */
/*{*/
if (c == '}') {
POP_STATE();
*wp++ = CSUBST;
*wp++ = /*{*/ '}';
} else if (c == '|') {
*wp++ = SPAT;
} else if (c == '(') {
*wp++ = OPAT;
*wp++ = ' '; /* simile for @ */
PUSH_STATE(SPATTERN);
} else
goto Sbase1;
break;
case SBQUOTE:
if (c == '`') {
*wp++ = 0;
POP_STATE();
} else if (c == '\\') {
switch (c = getsc()) {
case '\\':
case '$': case '`':
*wp++ = c;
break;
case '"':
if (statep->ls_sbquote.indquotes) {
*wp++ = c;
break;
}
/* FALLTHRU */
default:
if (c) { /* trailing \ is lost */
*wp++ = '\\';
*wp++ = c;
}
break;
}
} else
*wp++ = c;
break;
case SWORD: /* ONEWORD */
goto Subst;
case SLETPAREN: /* LETEXPR: (( ... )) */
/*(*/
if (c == ')') {
if (statep->ls_sletparen.nparen > 0)
--statep->ls_sletparen.nparen;
/*(*/
else if ((c2 = getsc()) == ')') {
c = 0;
*wp++ = CQUOTE;
goto Done;
} else
ungetsc(c2);
} else if (c == '(')
/* parenthesis inside quotes and backslashes
* are lost, but at&t ksh doesn't count them
* either
*/
++statep->ls_sletparen.nparen;
goto Sbase2;
case SHEREDELIM: /* <<,<<- delimiter */
/* XXX chuck this state (and the next) - use
* the existing states ($ and \`..` should be
* stripped of their specialness after the
* fact).
*/
/* here delimiters need a special case since
* $ and `..` are not to be treated specially
*/
if (c == '\\') {
c = getsc();
if (c) { /* trailing \ is lost */
*wp++ = QCHAR;
*wp++ = c;
}
} else if (c == '\'') {
PUSH_STATE(SSQUOTE);
*wp++ = OQUOTE;
ignore_backslash_newline++;
} else if (c == '"') {
state = statep->ls_state = SHEREDQUOTE;
*wp++ = OQUOTE;
} else {
*wp++ = CHAR;
*wp++ = c;
}
break;
case SHEREDQUOTE: /* " in <<,<<- delimiter */
if (c == '"') {
*wp++ = CQUOTE;
state = statep->ls_state = SHEREDELIM;
} else {
if (c == '\\') {
switch (c = getsc()) {
case '\\': case '"':
case '$': case '`':
break;
default:
if (c) { /* trailing \ lost */
*wp++ = CHAR;
*wp++ = '\\';
}
break;
}
}
*wp++ = CHAR;
*wp++ = c;
}
break;
case SPATTERN: /* in *(...|...) pattern (*+?@!) */
if ( /*(*/ c == ')') {
*wp++ = CPAT;
POP_STATE();
} else if (c == '|') {
*wp++ = SPAT;
} else if (c == '(') {
*wp++ = OPAT;
*wp++ = ' '; /* simile for @ */
PUSH_STATE(SPATTERN);
} else
goto Sbase1;
break;
}
}
Done:
Xcheck(ws, wp);
if (statep != &states[1])
/* XXX figure out what is missing */
yyerror("no closing quote\n");
/* This done to avoid tests for SHEREDELIM wherever SBASE tested */
if (state == SHEREDELIM)
state = SBASE;
dp = Xstring(ws, wp);
if ((c == '<' || c == '>') && state == SBASE &&
((c2 = Xlength(ws, wp)) == 0 ||
(c2 == 2 && dp[0] == CHAR && digit(dp[1])))) {
struct ioword *iop = (struct ioword *) alloc(sizeof(*iop), ATEMP);
if (c2 == 2)
iop->unit = dp[1] - '0';
else
iop->unit = c == '>'; /* 0 for <, 1 for > */
c2 = getsc();
/* <<, >>, <> are ok, >< is not */
if (c == c2 || (c == '<' && c2 == '>')) {
iop->flag = c == c2 ?
(c == '>' ? IOCAT : IOHERE) : IORDWR;
if (iop->flag == IOHERE) {
if ((c2 = getsc()) == '-')
iop->flag |= IOSKIP;
else
ungetsc(c2);
}
} else if (c2 == '&')
iop->flag = IODUP | (c == '<' ? IORDUP : 0);
else {
iop->flag = c == '>' ? IOWRITE : IOREAD;
if (c == '>' && c2 == '|')
iop->flag |= IOCLOB;
else
ungetsc(c2);
}
iop->name = NULL;
iop->delim = NULL;
iop->heredoc = NULL;
Xfree(ws, wp); /* free word */
yylval.iop = iop;
return REDIR;
}
if (wp == dp && state == SBASE) {
Xfree(ws, wp); /* free word */
/* no word, process LEX1 character */
switch (c) {
default:
return c;
case '|':
case '&':
case ';':
if ((c2 = getsc()) == c)
c = (c == ';') ? BREAK :
(c == '|') ? LOGOR :
(c == '&') ? LOGAND :
YYERRCODE;
else if (c == '|' && c2 == '&')
c = COPROC;
else
ungetsc(c2);
return c;
case '\n':
gethere();
if (cf & CONTIN)
goto Again;
return c;
case '(': /*)*/
if ((c2 = getsc()) == '(') /*)*/
/* XXX need to handle ((...); (...)) */
c = MDPAREN;
else
ungetsc(c2);
return c;
/*(*/
case ')':
return c;
}
}
*wp++ = EOS; /* terminate word */
yylval.cp = Xclose(ws, wp);
if (state == SWORD || state == SLETPAREN) /* ONEWORD? */
return LWORD;
ungetsc(c); /* unget terminator */
/* copy word to unprefixed string ident */
for (sp = yylval.cp, dp = ident; dp < ident+IDENT && (c = *sp++) == CHAR; )
*dp++ = *sp++;
/* Make sure the ident array stays '\0' padded */
memset(dp, 0, (ident+IDENT) - dp + 1);
if (c != EOS)
*ident = '\0'; /* word is not unquoted */
if (*ident != '\0' && (cf&(KEYWORD|ALIAS))) {
struct tbl *p;
int h = hash(ident);
/* { */
if ((cf & KEYWORD) && (p = ktsearch(&keywords, ident, h)) &&
(!(cf & ESACONLY) || p->val.i == ESAC || p->val.i == '}')) {
afree(yylval.cp, ATEMP);
return p->val.i;
}
if ((cf & ALIAS) && (p = ktsearch(&aliases, ident, h)) &&
(p->flag & ISSET)) {
Source *s;
for (s = source; s->type == SALIAS; s = s->next)
if (s->u.tblp == p)
return LWORD;
/* push alias expansion */
s = pushs(SALIAS, source->areap);
s->start = s->str = p->val.s;
s->u.tblp = p;
s->next = source;
source = s;
afree(yylval.cp, ATEMP);
goto Again;
}
}
return LWORD;
}
static void
gethere(void)
{
struct ioword **p;
for (p = heres; p < herep; p++)
readhere(*p);
herep = heres;
}
/*
* read "<<word" text into temp file
*/
static void
readhere(struct ioword *iop)
{
int c;
char *volatile eof;
char *eofp;
int skiptabs;
XString xs;
char *xp;
int xpos;
eof = evalstr(iop->delim, 0);
if (!(iop->flag & IOEVAL))
ignore_backslash_newline++;
Xinit(xs, xp, 256, ATEMP);
for (;;) {
eofp = eof;
skiptabs = iop->flag & IOSKIP;
xpos = Xsavepos(xs, xp);
while ((c = getsc()) != 0) {
if (skiptabs) {
if (c == '\t')
continue;
skiptabs = 0;
}
if (c != *eofp)
break;
Xcheck(xs, xp);
Xput(xs, xp, c);
eofp++;
}
/* Allow EOF here so commands with out trailing newlines
* will work (eg, ksh -c '...', $(...), etc).
*/
if (*eofp == '\0' && (c == 0 || c == '\n')) {
xp = Xrestpos(xs, xp, xpos);
break;
}
ungetsc(c);
while ((c = getsc()) != '\n') {
if (c == 0)
yyerror("here document '%s' unclosed\n", eof);
Xcheck(xs, xp);
Xput(xs, xp, c);
}
Xcheck(xs, xp);
Xput(xs, xp, c);
}
Xput(xs, xp, '\0');
iop->heredoc = Xclose(xs, xp);
if (!(iop->flag & IOEVAL))
ignore_backslash_newline--;
}
void
yyerror(const char *fmt, ...)
{
va_list va;
/* pop aliases and re-reads */
while (source->type == SALIAS || source->type == SREREAD)
source = source->next;
source->str = null; /* zap pending input */
error_prefix(true);
va_start(va, fmt);
shf_vfprintf(shl_out, fmt, va);
va_end(va);
errorf(null);
}
/*
* input for yylex with alias expansion
*/
Source *
pushs(int type, Area *areap)
{
Source *s;
s = (Source *) alloc(sizeof(Source), areap);
s->type = type;
s->str = null;
s->start = NULL;
s->line = 0;
s->errline = 0;
s->file = NULL;
s->flags = 0;
s->next = NULL;
s->areap = areap;
if (type == SFILE || type == SSTDIN) {
char *dummy;
Xinit(s->xs, dummy, 256, s->areap);
} else
memset(&s->xs, 0, sizeof(s->xs));
return s;
}
static int
getsc__(void)
{
Source *s = source;
int c;
while ((c = *s->str++) == 0) {
s->str = NULL; /* return 0 for EOF by default */
switch (s->type) {
case SEOF:
s->str = null;
return 0;
case SSTDIN:
case SFILE:
getsc_line(s);
break;
case SWSTR:
break;
case SSTRING:
break;
case SWORDS:
s->start = s->str = *s->u.strv++;
s->type = SWORDSEP;
break;
case SWORDSEP:
if (*s->u.strv == NULL) {
s->start = s->str = newline;
s->type = SEOF;
} else {
s->start = s->str = space;
s->type = SWORDS;
}
break;
case SALIAS:
if (s->flags & SF_ALIASEND) {
/* pass on an unused SF_ALIAS flag */
source = s->next;
source->flags |= s->flags & SF_ALIAS;
s = source;
} else if (*s->u.tblp->val.s &&
isspace(strchr(s->u.tblp->val.s, 0)[-1])) {
source = s = s->next; /* pop source stack */
/* Note that this alias ended with a space,
* enabling alias expansion on the following
* word.
*/
s->flags |= SF_ALIAS;
} else {
/* At this point, we need to keep the current
* alias in the source list so recursive
* aliases can be detected and we also need
* to return the next character. Do this
* by temporarily popping the alias to get
* the next character and then put it back
* in the source list with the SF_ALIASEND
* flag set.
*/
source = s->next; /* pop source stack */
source->flags |= s->flags & SF_ALIAS;
c = getsc__();
if (c) {
s->flags |= SF_ALIASEND;
s->ugbuf[0] = c; s->ugbuf[1] = '\0';
s->start = s->str = s->ugbuf;
s->next = source;
source = s;
} else {
s = source;
/* avoid reading eof twice */
s->str = NULL;
break;
}
}
continue;
case SREREAD:
if (s->start != s->ugbuf) /* yuck */
afree(s->u.freeme, ATEMP);
source = s = s->next;
continue;
}
if (s->str == NULL) {
s->type = SEOF;
s->start = s->str = null;
return '\0';
}
if (s->flags & SF_ECHO) {
shf_puts(s->str, shl_out);
shf_flush(shl_out);
}
}
return c;
}
static void
getsc_line(Source *s)
{
char *xp = Xstring(s->xs, xp);
int interactive = Flag(FTALKING) && s->type == SSTDIN;
int have_tty = interactive && (s->flags & SF_TTY);
/* Done here to ensure nothing odd happens when a timeout occurs */
XcheckN(s->xs, xp, LINE);
*xp = '\0';
s->start = s->str = xp;
if (have_tty && ksh_tmout) {
ksh_tmout_state = TMOUT_READING;
alarm(ksh_tmout);
}
if (have_tty && (Flag(FVI) || Flag(FEMACS) || Flag(FGMACS))) {
int nread;
nread = x_read(xp, LINE);
if (nread < 0) /* read error */
nread = 0;
xp[nread] = '\0';
xp += nread;
} else {
if (interactive) {
pprompt(prompt, 0);
} else
s->line++;
while (1) {
char *p = shf_getse(xp, Xnleft(s->xs, xp), s->u.shf);
if (!p && shf_error(s->u.shf) &&
shf_errno(s->u.shf) == EINTR) {
shf_clearerr(s->u.shf);
if (trap)
runtraps(0);
continue;
}
if (!p || (xp = p, xp[-1] == '\n'))
break;
/* double buffer size */
xp++; /* move past null so doubling works... */
XcheckN(s->xs, xp, Xlength(s->xs, xp));
xp--; /* ...and move back again */
}
/* flush any unwanted input so other programs/builtins
* can read it. Not very optimal, but less error prone
* than flushing else where, dealing with redirections,
* etc..
* todo: reduce size of shf buffer (~128?) if SSTDIN
*/
if (s->type == SSTDIN)
shf_flush(s->u.shf);
}
/* XXX: temporary kludge to restore source after a
* trap may have been executed.
*/
source = s;
if (have_tty && ksh_tmout) {
ksh_tmout_state = TMOUT_EXECUTING;
alarm(0);
}
s->start = s->str = Xstring(s->xs, xp);
strip_nuls(Xstring(s->xs, xp), Xlength(s->xs, xp));
/* Note: if input is all nulls, this is not eof */
if (Xlength(s->xs, xp) == 0) { /* EOF */
if (s->type == SFILE)
shf_fdclose(s->u.shf);
s->str = NULL;
} else if (interactive) {
char *p = Xstring(s->xs, xp);
if (cur_prompt == PS1)
while (*p && ctype(*p, C_IFS) && ctype(*p, C_IFSWS))
p++;
if (*p) {
s->line++;
histsave(s->line, s->str, 1);
}
}
if (interactive)
set_prompt(PS2, NULL);
}
void
set_prompt(int to, Source *s)
{
cur_prompt = to;
switch (to) {
case PS1: /* command */
/* Substitute ! and !! here, before substitutions are done
* so ! in expanded variables are not expanded.
* NOTE: this is not what at&t ksh does (it does it after
* substitutions, POSIX doesn't say which is to be done.
*/
{
struct shf *shf;
char * volatile ps1;
Area *saved_atemp;
ps1 = str_val(global("PS1"));
shf = shf_sopen(NULL, strlen(ps1) * 2,
SHF_WR | SHF_DYNAMIC, NULL);
while (*ps1)
if (*ps1 != '!' || *++ps1 == '!')
shf_putchar(*ps1++, shf);
else
shf_fprintf(shf, "%d",
s ? s->line + 1 : 0);
ps1 = shf_sclose(shf);
saved_atemp = ATEMP;
newenv(E_ERRH);
if (sigsetjmp(e->jbuf, 0)) {
prompt = safe_prompt;
/* Don't print an error - assume it has already
* been printed. Reason is we may have forked
* to run a command and the child may be
* unwinding its stack through this code as it
* exits.
*/
} else
prompt = str_save(substitute(ps1, 0),
saved_atemp);
quitenv(NULL);
}
break;
case PS2: /* command continuation */
prompt = str_val(global("PS2"));
break;
}
}
/* See also related routine, promptlen() in edit.c */
void
pprompt(const char *cp, int ntruncate)
{
shf_puts(cp + ntruncate, shl_out);
shf_flush(shl_out);
}
/* Read the variable part of a ${...} expression (ie, up to but not including
* the :[-+?=#%] or close-brace.
*/
static char *
get_brace_var(XString *wsp, char *wp)
{
enum parse_state {
PS_INITIAL, PS_SAW_HASH, PS_IDENT,
PS_NUMBER, PS_VAR1, PS_END
}
state;
char c;
state = PS_INITIAL;
while (1) {
c = getsc();
/* State machine to figure out where the variable part ends. */
switch (state) {
case PS_INITIAL:
if (c == '#') {
state = PS_SAW_HASH;
break;
}
/* FALLTHRU */
case PS_SAW_HASH:
if (letter(c))
state = PS_IDENT;
else if (digit(c))
state = PS_NUMBER;
else if (ctype(c, C_VAR1))
state = PS_VAR1;
else
state = PS_END;
break;
case PS_IDENT:
if (!letnum(c)) {
state = PS_END;
if (c == '[') {
char *tmp, *p;
if (!arraysub(&tmp))
yyerror("missing ]\n");
*wp++ = c;
for (p = tmp; *p; ) {
Xcheck(*wsp, wp);
*wp++ = *p++;
}
afree(tmp, ATEMP);
c = getsc(); /* the ] */
}
}
break;
case PS_NUMBER:
if (!digit(c))
state = PS_END;
break;
case PS_VAR1:
state = PS_END;
break;
case PS_END: /* keep gcc happy */
break;
}
if (state == PS_END) {
*wp++ = '\0'; /* end of variable part */
ungetsc(c);
break;
}
Xcheck(*wsp, wp);
*wp++ = c;
}
return wp;
}
/*
* Save an array subscript - returns true if matching bracket found, false
* if eof or newline was found.
* (Returned string double null terminated)
*/
static int
arraysub(char **strp)
{
XString ws;
char *wp;
char c;
int depth = 1; /* we are just past the initial [ */
Xinit(ws, wp, 32, ATEMP);
do {
c = getsc();
Xcheck(ws, wp);
*wp++ = c;
if (c == '[')
depth++;
else if (c == ']')
depth--;
} while (depth > 0 && c && c != '\n');
*wp++ = '\0';
*strp = Xclose(ws, wp);
return depth == 0 ? 1 : 0;
}
/* Unget a char: handles case when we are already at the start of the buffer */
static const char *
ungetsc(int c)
{
if (backslash_skip)
backslash_skip--;
/* Don't unget eof... */
if (source->str == null && c == '\0')
return source->str;
if (source->str > source->start)
source->str--;
else {
Source *s;
s = pushs(SREREAD, source->areap);
s->ugbuf[0] = c; s->ugbuf[1] = '\0';
s->start = s->str = s->ugbuf;
s->next = source;
source = s;
}
return source->str;
}
/* Called to get a char that isn't a \newline sequence. */
static int
getsc_bn(void)
{
int c, c2;
if (ignore_backslash_newline)
return getsc_();
if (backslash_skip == 1) {
backslash_skip = 2;
return getsc_();
}
backslash_skip = 0;
while (1) {
c = getsc_();
if (c == '\\') {
if ((c2 = getsc_()) == '\n')
/* ignore the \newline; get the next char... */
continue;
ungetsc(c2);
backslash_skip = 1;
}
return c;
}
}
static Lex_state *
push_state_(State_info *si, Lex_state *old_end)
{
Lex_state *new = alloc(sizeof(Lex_state) * STATE_BSIZE, ATEMP);
new[0].ls_info.base = old_end;
si->base = &new[0];
si->end = &new[STATE_BSIZE];
return &new[1];
}
static Lex_state *
pop_state_(State_info *si, Lex_state *old_end)
{
Lex_state *old_base = si->base;
si->base = old_end->ls_info.base - STATE_BSIZE;
si->end = old_end->ls_info.base;
afree(old_base, ATEMP);
return si->base + STATE_BSIZE - 1;
}
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