mksh/main.c

1811 lines
39 KiB
C

/* $OpenBSD: main.c,v 1.47 2011/09/07 11:33:25 otto Exp $ */
/* $OpenBSD: tty.c,v 1.9 2006/03/14 22:08:01 deraadt Exp $ */
/* $OpenBSD: io.c,v 1.22 2006/03/17 16:30:13 millert Exp $ */
/* $OpenBSD: table.c,v 1.15 2012/02/19 07:52:30 otto Exp $ */
/*-
* Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
* 2011, 2012
* Thorsten Glaser <tg@mirbsd.org>
*
* Provided that these terms and disclaimer and all copyright notices
* are retained or reproduced in an accompanying document, permission
* is granted to deal in this work without restriction, including un-
* limited rights to use, publicly perform, distribute, sell, modify,
* merge, give away, or sublicence.
*
* This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
* the utmost extent permitted by applicable law, neither express nor
* implied; without malicious intent or gross negligence. In no event
* may a licensor, author or contributor be held liable for indirect,
* direct, other damage, loss, or other issues arising in any way out
* of dealing in the work, even if advised of the possibility of such
* damage or existence of a defect, except proven that it results out
* of said person's immediate fault when using the work as intended.
*/
#define EXTERN
#include "sh.h"
#if HAVE_LANGINFO_CODESET
#include <langinfo.h>
#endif
#if HAVE_SETLOCALE_CTYPE
#include <locale.h>
#endif
__RCSID("$MirOS: src/bin/mksh/main.c,v 1.225 2012/07/01 15:38:06 tg Exp $");
extern char **environ;
#ifndef MKSHRC_PATH
#define MKSHRC_PATH "~/.mkshrc"
#endif
#ifndef MKSH_DEFAULT_TMPDIR
#define MKSH_DEFAULT_TMPDIR "/tmp"
#endif
static uint8_t isuc(const char *);
static int main_init(int, const char *[], Source **, struct block **);
void chvt_reinit(void);
static void reclaim(void);
static void remove_temps(struct temp *);
static mksh_uari_t rndsetup(void);
#ifdef SIGWINCH
static void x_sigwinch(int);
#endif
static const char initifs[] = "IFS= \t\n";
static const char initsubs[] =
"${PS2=> } ${PS3=#? } ${PS4=+ } ${SECONDS=0} ${TMOUT=0}";
static const char *initcoms[] = {
Ttypeset, "-r", initvsn, NULL,
Ttypeset, "-x", "HOME", "PATH", "RANDOM", "SHELL", NULL,
Ttypeset, "-i10", "SECONDS", "TMOUT", NULL,
Talias,
"integer=typeset -i",
Tlocal_typeset,
/* not "alias -t --": hash -r needs to work */
"hash=alias -t",
"type=whence -v",
#if !defined(ANDROID) && !defined(MKSH_UNEMPLOYED)
/* not in Android for political reasons */
/* not in ARGE mksh due to no job control */
"stop=kill -STOP",
"suspend=kill -STOP $$",
#endif
"autoload=typeset -fu",
"functions=typeset -f",
"history=fc -l",
"nameref=typeset -n",
"nohup=nohup ",
Tr_fc_e_dash,
"source=PATH=$PATH:. command .",
"login=exec login",
NULL,
/* this is what AT&T ksh seems to track, with the addition of emacs */
Talias, "-tU",
"cat", "cc", "chmod", "cp", "date", "ed", "emacs", "grep", "ls",
"make", "mv", "pr", "rm", "sed", "sh", "vi", "who", NULL,
NULL
};
static const char *restr_com[] = {
Ttypeset, "-r", "PATH", "ENV", "SHELL", NULL
};
static bool initio_done;
/* top-level parsing and execution environment */
static struct env env;
struct env *e = &env;
static mksh_uari_t
rndsetup(void)
{
register uint32_t h;
struct {
ALLOC_ITEM alloc_INT;
void *dataptr, *stkptr, *mallocptr;
#if defined(__GLIBC__) && (__GLIBC__ >= 2)
sigjmp_buf jbuf;
#endif
struct timeval tv;
} *bufptr;
char *cp;
cp = alloc(sizeof(*bufptr) - ALLOC_SIZE, APERM);
#ifdef DEBUG
/* clear the allocated space, for valgrind */
memset(cp, 0, sizeof(*bufptr) - ALLOC_SIZE);
#endif
/* undo what alloc() did to the malloc result address */
bufptr = (void *)(cp - ALLOC_SIZE);
/* PIE or something similar provides us with deltas here */
bufptr->dataptr = &rndsetupstate;
/* ASLR in at least Windows, Linux, some BSDs */
bufptr->stkptr = &bufptr;
/* randomised malloc in BSD (and possibly others) */
bufptr->mallocptr = bufptr;
#if defined(__GLIBC__) && (__GLIBC__ >= 2)
/* glibc pointer guard */
sigsetjmp(bufptr->jbuf, 1);
#endif
/* introduce variation (and yes, second arg MBZ for portability) */
mksh_TIME(bufptr->tv);
NZATInit(h);
/* variation through pid, ppid, and the works */
NZATUpdateMem(h, &rndsetupstate, sizeof(rndsetupstate));
/* some variation, some possibly entropy, depending on OE */
NZATUpdateMem(h, bufptr, sizeof(*bufptr));
NZAATFinish(h);
afree(cp, APERM);
return ((mksh_uari_t)h);
}
void
chvt_reinit(void)
{
kshpid = procpid = getpid();
ksheuid = geteuid();
kshpgrp = getpgrp();
kshppid = getppid();
}
static const char *empty_argv[] = {
"mksh", NULL
};
static uint8_t
isuc(const char *cx) {
char *cp, *x;
uint8_t rv = 0;
if (!cx || !*cx)
return (0);
/* uppercase a string duplicate */
strdupx(x, cx, ATEMP);
cp = x;
while ((*cp = ksh_toupper(*cp)))
++cp;
/* check for UTF-8 */
if (strstr(x, "UTF-8") || strstr(x, "UTF8"))
rv = 1;
/* free copy and out */
afree(x, ATEMP);
return (rv);
}
static int
main_init(int argc, const char *argv[], Source **sp, struct block **lp)
{
int argi, i;
Source *s = NULL;
struct block *l;
unsigned char restricted, errexit, utf_flag;
char *cp;
const char *ccp, **wp;
struct tbl *vp;
struct stat s_stdin;
#if !defined(_PATH_DEFPATH) && defined(_CS_PATH)
ssize_t k;
#endif
/* do things like getpgrp() et al. */
chvt_reinit();
/* make sure argv[] is sane */
if (!*argv) {
argv = empty_argv;
argc = 1;
}
kshname = argv[0];
/* initialise permanent Area */
ainit(&aperm);
/* set up base environment */
env.type = E_NONE;
ainit(&env.area);
/* set up global l->vars and l->funs */
newblock();
/* Do this first so output routines (eg, errorf, shellf) can work */
initio();
/* determine the basename (without '-' or path) of the executable */
ccp = kshname;
goto begin_parse_kshname;
while ((i = ccp[argi++])) {
if (i == '/') {
ccp += argi;
begin_parse_kshname:
argi = 0;
if (*ccp == '-')
++ccp;
}
}
if (!*ccp)
ccp = empty_argv[0];
/* define built-in commands and see if we were called as one */
ktinit(APERM, &builtins,
/* currently up to 50 builtins: 75% of 128 = 2^7 */
7);
for (i = 0; mkshbuiltins[i].name != NULL; i++)
if (!strcmp(ccp, builtin(mkshbuiltins[i].name,
mkshbuiltins[i].func)))
Flag(FAS_BUILTIN) = 1;
if (!Flag(FAS_BUILTIN)) {
/* check for -T option early */
argi = parse_args(argv, OF_FIRSTTIME, NULL);
if (argi < 0)
return (1);
#ifdef MKSH_BINSHREDUCED
/* set FSH if we're called as -sh or /bin/sh or so */
if (!strcmp(ccp, "sh"))
change_flag(FSH, OF_FIRSTTIME, 1);
#endif
}
initvar();
initctypes();
inittraps();
coproc_init();
/* set up variable and command dictionaries */
ktinit(APERM, &taliases, 0);
ktinit(APERM, &aliases, 0);
#ifndef MKSH_NOPWNAM
ktinit(APERM, &homedirs, 0);
#endif
/* define shell keywords */
initkeywords();
init_histvec();
#ifdef TIOCGWINSZ
/* try to initialise tty size before importing environment */
tty_init(false, false);
change_winsz();
tty_close();
#endif
#ifdef _PATH_DEFPATH
def_path = _PATH_DEFPATH;
#else
#ifdef _CS_PATH
if ((k = confstr(_CS_PATH, NULL, 0)) > 0 &&
confstr(_CS_PATH, cp = alloc(k + 1, APERM), k + 1) == k + 1)
def_path = cp;
else
#endif
/*
* this is uniform across all OSes unless it
* breaks somewhere; don't try to optimise,
* e.g. add stuff for Interix or remove /usr
* for HURD, because e.g. Debian GNU/HURD is
* "keeping a regular /usr"; this is supposed
* to be a sane 'basic' default PATH
*/
def_path = "/bin:/usr/bin:/sbin:/usr/sbin";
#endif
/*
* Set PATH to def_path (will set the path global variable).
* (import of environment below will probably change this setting).
*/
vp = global("PATH");
/* setstr can't fail here */
setstr(vp, def_path, KSH_RETURN_ERROR);
/*
* Turn on nohup by default for now - will change to off
* by default once people are aware of its existence
* (AT&T ksh does not have a nohup option - it always sends
* the hup).
*/
Flag(FNOHUP) = 1;
/*
* Turn on brace expansion by default. AT&T kshs that have
* alternation always have it on.
*/
Flag(FBRACEEXPAND) = 1;
#ifndef MKSH_NO_CMDLINE_EDITING
/*
* Set edit mode to emacs by default, may be overridden
* by the environment or the user. Also, we want tab completion
* on in vi by default.
*/
change_flag(FEMACS, OF_SPECIAL, 1);
#if !MKSH_S_NOVI
Flag(FVITABCOMPLETE) = 1;
#endif
#endif
/* import environment */
if (environ != NULL)
for (wp = (const char **)environ; *wp != NULL; wp++)
typeset(*wp, IMPORT | EXPORT, 0, 0, 0);
/* for security */
typeset(initifs, 0, 0, 0, 0);
/* assign default shell variable values */
substitute(initsubs, 0);
/* Figure out the current working directory and set $PWD */
vp = global("PWD");
cp = str_val(vp);
/* Try to use existing $PWD if it is valid */
set_current_wd((cp[0] == '/' && test_eval(NULL, TO_FILEQ, cp, ".",
true)) ? cp : NULL);
if (current_wd[0])
simplify_path(current_wd);
/* Only set pwd if we know where we are or if it had a bogus value */
if (current_wd[0] || *cp)
/* setstr can't fail here */
setstr(vp, current_wd, KSH_RETURN_ERROR);
for (wp = initcoms; *wp != NULL; wp++) {
shcomexec(wp);
while (*wp != NULL)
wp++;
}
setint_n(global("COLUMNS"), 0, 10);
setint_n(global("LINES"), 0, 10);
setint_n(global("OPTIND"), 1, 10);
kshuid = getuid();
kshgid = getgid();
kshegid = getegid();
safe_prompt = ksheuid ? "$ " : "# ";
vp = global("PS1");
/* Set PS1 if unset or we are root and prompt doesn't contain a # */
if (!(vp->flag & ISSET) ||
(!ksheuid && !strchr(str_val(vp), '#')))
/* setstr can't fail here */
setstr(vp, safe_prompt, KSH_RETURN_ERROR);
setint_n((vp = global("PGRP")), (mksh_uari_t)kshpgrp, 10);
vp->flag |= INT_U;
setint_n((vp = global("PPID")), (mksh_uari_t)kshppid, 10);
vp->flag |= INT_U;
setint_n((vp = global("USER_ID")), (mksh_uari_t)ksheuid, 10);
vp->flag |= INT_U;
setint_n((vp = global("KSHUID")), (mksh_uari_t)kshuid, 10);
vp->flag |= INT_U;
setint_n((vp = global("KSHEGID")), (mksh_uari_t)kshegid, 10);
vp->flag |= INT_U;
setint_n((vp = global("KSHGID")), (mksh_uari_t)kshgid, 10);
vp->flag |= INT_U;
setint_n((vp = global("RANDOM")), rndsetup(), 10);
vp->flag |= INT_U;
setint_n((vp_pipest = global("PIPESTATUS")), 0, 10);
/* Set this before parsing arguments */
Flag(FPRIVILEGED) = kshuid != ksheuid || kshgid != kshegid;
/* this to note if monitor is set on command line (see below) */
#ifndef MKSH_UNEMPLOYED
Flag(FMONITOR) = 127;
#endif
/* this to note if utf-8 mode is set on command line (see below) */
UTFMODE = 2;
if (!Flag(FAS_BUILTIN)) {
argi = parse_args(argv, OF_CMDLINE, NULL);
if (argi < 0)
return (1);
}
#ifdef DEBUG
/* test wraparound of arithmetic types */
{
volatile long xl;
volatile unsigned long xul;
volatile int xi;
volatile unsigned int xui;
volatile mksh_ari_t xa;
volatile mksh_uari_t xua, xua2;
volatile uint8_t xc;
xa = 2147483647;
xua = 2147483647;
++xa;
++xua;
xua2 = xa;
xl = xa;
xul = xua;
xa = 0;
xua = 0;
--xa;
--xua;
xi = xa;
xui = xua;
xa = -1;
xua = xa;
++xa;
++xua;
xc = 0;
--xc;
if ((xua2 != 2147483648UL) ||
(xl != -2147483648L) || (xul != 2147483648UL) ||
(xi != -1) || (xui != 4294967295U) ||
(xa != 0) || (xua != 0) || (xc != 255))
errorf("integer wraparound test failed");
}
#endif
/* process this later only, default to off (hysterical raisins) */
utf_flag = UTFMODE;
UTFMODE = 0;
if (Flag(FAS_BUILTIN)) {
/* auto-detect from environment variables, always */
utf_flag = 3;
} else if (Flag(FCOMMAND)) {
s = pushs(SSTRINGCMDLINE, ATEMP);
if (!(s->start = s->str = argv[argi++]))
errorf("%s %s", "-c", "requires an argument");
#ifdef MKSH_MIDNIGHTBSD01ASH_COMPAT
/* compatibility to MidnightBSD 0.1 /bin/sh (kludge) */
if (Flag(FSH) && argv[argi] && !strcmp(argv[argi], "--"))
++argi;
#endif
if (argv[argi])
kshname = argv[argi++];
} else if (argi < argc && !Flag(FSTDIN)) {
s = pushs(SFILE, ATEMP);
s->file = argv[argi++];
s->u.shf = shf_open(s->file, O_RDONLY, 0,
SHF_MAPHI | SHF_CLEXEC);
if (s->u.shf == NULL) {
shl_stdout_ok = false;
warningf(true, "%s: %s", s->file, strerror(errno));
/* mandated by SUSv4 */
exstat = 127;
unwind(LERROR);
}
kshname = s->file;
} else {
Flag(FSTDIN) = 1;
s = pushs(SSTDIN, ATEMP);
s->file = "<stdin>";
s->u.shf = shf_fdopen(0, SHF_RD | can_seek(0),
NULL);
if (isatty(0) && isatty(2)) {
Flag(FTALKING) = Flag(FTALKING_I) = 1;
/* The following only if isatty(0) */
s->flags |= SF_TTY;
s->u.shf->flags |= SHF_INTERRUPT;
s->file = NULL;
}
}
/* this bizarreness is mandated by POSIX */
if (fstat(0, &s_stdin) >= 0 && S_ISCHR(s_stdin.st_mode) &&
Flag(FTALKING))
reset_nonblock(0);
/* initialise job control */
j_init();
/* Do this after j_init(), as tty_fd is not initialised until then */
if (Flag(FTALKING)) {
if (utf_flag == 2) {
#ifndef MKSH_ASSUME_UTF8
/* auto-detect from locale or environment */
utf_flag = 4;
#elif MKSH_ASSUME_UTF8
utf_flag = 1;
#else
/* always disable UTF-8 (for interactive) */
utf_flag = 0;
#endif
}
#ifndef MKSH_NO_CMDLINE_EDITING
x_init();
#endif
}
#ifdef SIGWINCH
sigtraps[SIGWINCH].flags |= TF_SHELL_USES;
setsig(&sigtraps[SIGWINCH], x_sigwinch,
SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
#endif
l = e->loc;
if (Flag(FAS_BUILTIN)) {
l->argc = argc;
l->argv = argv;
l->argv[0] = ccp;
} else {
l->argc = argc - argi;
l->argv = &argv[argi - 1];
l->argv[0] = kshname;
getopts_reset(1);
}
/* divine the initial state of the utf8-mode Flag */
ccp = null;
switch (utf_flag) {
/* auto-detect from locale or environment */
case 4:
#if HAVE_SETLOCALE_CTYPE
ccp = setlocale(LC_CTYPE, "");
#if HAVE_LANGINFO_CODESET
if (!isuc(ccp))
ccp = nl_langinfo(CODESET);
#endif
if (!isuc(ccp))
ccp = null;
/* FALLTHROUGH */
#endif
/* auto-detect from environment */
case 3:
/* these were imported from environ earlier */
if (ccp == null)
ccp = str_val(global("LC_ALL"));
if (ccp == null)
ccp = str_val(global("LC_CTYPE"));
if (ccp == null)
ccp = str_val(global("LANG"));
UTFMODE = isuc(ccp);
break;
/* not set on command line, not FTALKING */
case 2:
/* unknown values */
default:
utf_flag = 0;
/* FALLTHROUGH */
/* known values */
case 1:
case 0:
UTFMODE = utf_flag;
break;
}
/* Disable during .profile/ENV reading */
restricted = Flag(FRESTRICTED);
Flag(FRESTRICTED) = 0;
errexit = Flag(FERREXIT);
Flag(FERREXIT) = 0;
/*
* Do this before profile/$ENV so that if it causes problems in them,
* user will know why things broke.
*/
if (!current_wd[0] && Flag(FTALKING))
warningf(false, "can't determine current directory");
if (Flag(FLOGIN)) {
include(MKSH_SYSTEM_PROFILE, 0, NULL, 1);
if (!Flag(FPRIVILEGED))
include(substitute("$HOME/.profile", 0), 0,
NULL, 1);
}
if (Flag(FPRIVILEGED))
include(MKSH_SUID_PROFILE, 0, NULL, 1);
else if (Flag(FTALKING)) {
char *env_file;
/* include $ENV */
env_file = substitute(substitute("${ENV:-" MKSHRC_PATH "}", 0),
DOTILDE);
if (*env_file != '\0')
include(env_file, 0, NULL, 1);
}
if (restricted) {
shcomexec(restr_com);
/* After typeset command... */
Flag(FRESTRICTED) = 1;
}
Flag(FERREXIT) = errexit;
if (Flag(FTALKING) && s)
hist_init(s);
else
/* set after ENV */
Flag(FTRACKALL) = 1;
alarm_init();
*sp = s;
*lp = l;
return (0);
}
/* this indirection barrier reduces stack usage during normal operation */
int
main(int argc, const char *argv[])
{
int rv;
Source *s;
struct block *l;
if ((rv = main_init(argc, argv, &s, &l)) == 0) {
if (Flag(FAS_BUILTIN)) {
rv = shcomexec(l->argv);
} else {
shell(s, true);
/* NOTREACHED */
}
}
return (rv);
}
int
include(const char *name, int argc, const char **argv, int intr_ok)
{
Source *volatile s = NULL;
struct shf *shf;
const char **volatile old_argv;
volatile int old_argc;
int i;
shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
if (shf == NULL)
return (-1);
if (argv) {
old_argv = e->loc->argv;
old_argc = e->loc->argc;
} else {
old_argv = NULL;
old_argc = 0;
}
newenv(E_INCL);
if ((i = kshsetjmp(e->jbuf))) {
quitenv(s ? s->u.shf : NULL);
if (old_argv) {
e->loc->argv = old_argv;
e->loc->argc = old_argc;
}
switch (i) {
case LRETURN:
case LERROR:
/* see below */
return (exstat & 0xFF);
case LINTR:
/*
* intr_ok is set if we are including .profile or $ENV.
* If user ^Cs out, we don't want to kill the shell...
*/
if (intr_ok && (exstat - 128) != SIGTERM)
return (1);
/* FALLTHROUGH */
case LEXIT:
case LLEAVE:
case LSHELL:
unwind(i);
/* NOTREACHED */
default:
internal_errorf("%s %d", "include", i);
/* NOTREACHED */
}
}
if (argv) {
e->loc->argv = argv;
e->loc->argc = argc;
}
s = pushs(SFILE, ATEMP);
s->u.shf = shf;
strdupx(s->file, name, ATEMP);
i = shell(s, false);
quitenv(s->u.shf);
if (old_argv) {
e->loc->argv = old_argv;
e->loc->argc = old_argc;
}
/* & 0xff to ensure value not -1 */
return (i & 0xFF);
}
/* spawn a command into a shell optionally keeping track of the line number */
int
command(const char *comm, int line)
{
Source *s;
s = pushs(SSTRING, ATEMP);
s->start = s->str = comm;
s->line = line;
return (shell(s, false));
}
/*
* run the commands from the input source, returning status.
*/
int
shell(Source * volatile s, volatile bool toplevel)
{
struct op *t;
volatile bool wastty = tobool(s->flags & SF_TTY);
volatile uint8_t attempts = 13;
volatile bool interactive = Flag(FTALKING) && toplevel;
volatile bool sfirst = true;
Source *volatile old_source = source;
int i;
newenv(E_PARSE);
if (interactive)
really_exit = false;
switch ((i = kshsetjmp(e->jbuf))) {
case 0:
break;
case LINTR:
/* we get here if SIGINT not caught or ignored */
case LERROR:
case LSHELL:
if (interactive) {
if (i == LINTR)
shellf("\n");
/*
* Reset any eof that was read as part of a
* multiline command.
*/
if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
s->type = SSTDIN;
/*
* Used by exit command to get back to
* top level shell. Kind of strange since
* interactive is set if we are reading from
* a tty, but to have stopped jobs, one only
* needs FMONITOR set (not FTALKING/SF_TTY)...
*/
/* toss any input we have so far */
s->start = s->str = null;
break;
}
/* FALLTHROUGH */
case LEXIT:
case LLEAVE:
case LRETURN:
source = old_source;
quitenv(NULL);
/* keep on going */
unwind(i);
/* NOTREACHED */
default:
source = old_source;
quitenv(NULL);
internal_errorf("%s %d", "shell", i);
/* NOTREACHED */
}
while (/* CONSTCOND */ 1) {
if (trap)
runtraps(0);
if (s->next == NULL) {
if (Flag(FVERBOSE))
s->flags |= SF_ECHO;
else
s->flags &= ~SF_ECHO;
}
if (interactive) {
j_notify();
set_prompt(PS1, s);
}
t = compile(s, sfirst);
sfirst = false;
if (t != NULL && t->type == TEOF) {
if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
shellf("Use 'exit' to leave mksh\n");
s->type = SSTDIN;
} else if (wastty && !really_exit &&
j_stopped_running()) {
really_exit = true;
s->type = SSTDIN;
} else {
/*
* this for POSIX which says EXIT traps
* shall be taken in the environment
* immediately after the last command
* executed.
*/
if (toplevel)
unwind(LEXIT);
break;
}
}
if (t && (!Flag(FNOEXEC) || (s->flags & SF_TTY)))
exstat = execute(t, 0, NULL);
if (t != NULL && t->type != TEOF && interactive && really_exit)
really_exit = false;
reclaim();
}
quitenv(NULL);
source = old_source;
return (exstat);
}
/* return to closest error handler or shell(), exit if none found */
void
unwind(int i)
{
/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
if (i == LEXIT || (Flag(FERREXIT) && (i == LERROR || i == LINTR) &&
sigtraps[ksh_SIGEXIT].trap)) {
++trap_nested;
runtrap(&sigtraps[ksh_SIGEXIT], trap_nested == 1);
--trap_nested;
i = LLEAVE;
} else if (Flag(FERREXIT) && (i == LERROR || i == LINTR)) {
++trap_nested;
runtrap(&sigtraps[ksh_SIGERR], trap_nested == 1);
--trap_nested;
i = LLEAVE;
}
while (/* CONSTCOND */ 1) {
switch (e->type) {
case E_PARSE:
case E_FUNC:
case E_INCL:
case E_LOOP:
case E_ERRH:
kshlongjmp(e->jbuf, i);
/* NOTREACHED */
case E_NONE:
if (i == LINTR)
e->flags |= EF_FAKE_SIGDIE;
/* FALLTHROUGH */
default:
quitenv(NULL);
}
}
}
void
newenv(int type)
{
struct env *ep;
char *cp;
/*
* struct env includes ALLOC_ITEM for alignment constraints
* so first get the actually used memory, then assign it
*/
cp = alloc(sizeof(struct env) - ALLOC_SIZE, ATEMP);
/* undo what alloc() did to the malloc result address */
ep = (void *)(cp - ALLOC_SIZE);
/* initialise public members of struct env (not the ALLOC_ITEM) */
ainit(&ep->area);
ep->oenv = e;
ep->loc = e->loc;
ep->savefd = NULL;
ep->temps = NULL;
ep->type = type;
ep->flags = 0;
/* jump buffer is invalid because flags == 0 */
e = ep;
}
void
quitenv(struct shf *shf)
{
struct env *ep = e;
char *cp;
int fd;
if (ep->oenv && ep->oenv->loc != ep->loc)
popblock();
if (ep->savefd != NULL) {
for (fd = 0; fd < NUFILE; fd++)
/* if ep->savefd[fd] < 0, means fd was closed */
if (ep->savefd[fd])
restfd(fd, ep->savefd[fd]);
if (ep->savefd[2])
/* Clear any write errors */
shf_reopen(2, SHF_WR, shl_out);
}
/*
* Bottom of the stack.
* Either main shell is exiting or cleanup_parents_env() was called.
*/
if (ep->oenv == NULL) {
if (ep->type == E_NONE) {
/* Main shell exiting? */
#if HAVE_PERSISTENT_HISTORY
if (Flag(FTALKING))
hist_finish();
#endif
j_exit();
if (ep->flags & EF_FAKE_SIGDIE) {
int sig = exstat - 128;
/*
* ham up our death a bit (AT&T ksh
* only seems to do this for SIGTERM)
* Don't do it for SIGQUIT, since we'd
* dump a core..
*/
if ((sig == SIGINT || sig == SIGTERM) &&
(kshpgrp == kshpid)) {
setsig(&sigtraps[sig], SIG_DFL,
SS_RESTORE_CURR | SS_FORCE);
kill(0, sig);
}
}
}
if (shf)
shf_close(shf);
reclaim();
exit(exstat);
}
if (shf)
shf_close(shf);
reclaim();
e = e->oenv;
/* free the struct env - tricky due to the ALLOC_ITEM inside */
cp = (void *)ep;
afree(cp + ALLOC_SIZE, ATEMP);
}
/* Called after a fork to cleanup stuff left over from parents environment */
void
cleanup_parents_env(void)
{
struct env *ep;
int fd;
mkssert(e != NULL);
/*
* Don't clean up temporary files - parent will probably need them.
* Also, can't easily reclaim memory since variables, etc. could be
* anywhere.
*/
/* close all file descriptors hiding in savefd */
for (ep = e; ep; ep = ep->oenv) {
if (ep->savefd) {
for (fd = 0; fd < NUFILE; fd++)
if (ep->savefd[fd] > 0)
close(ep->savefd[fd]);
afree(ep->savefd, &ep->area);
ep->savefd = NULL;
}
}
e->oenv = NULL;
}
/* Called just before an execve cleanup stuff temporary files */
void
cleanup_proc_env(void)
{
struct env *ep;
for (ep = e; ep; ep = ep->oenv)
remove_temps(ep->temps);
}
/* remove temp files and free ATEMP Area */
static void
reclaim(void)
{
remove_temps(e->temps);
e->temps = NULL;
afreeall(&e->area);
}
static void
remove_temps(struct temp *tp)
{
for (; tp != NULL; tp = tp->next)
if (tp->pid == procpid)
unlink(tp->tffn);
}
/*
* Initialise tty_fd. Used for saving/reseting tty modes upon
* foreground job completion and for setting up tty process group.
*/
void
tty_init(bool init_ttystate, bool need_tty)
{
bool do_close = true;
int tfd;
if (tty_fd >= 0) {
close(tty_fd);
tty_fd = -1;
}
tty_devtty = true;
#ifdef _UWIN
/*XXX imake style */
if (isatty(3)) {
/* fd 3 on UWIN _is_ /dev/tty (or our controlling tty) */
tfd = 3;
do_close = false;
} else
#endif
if ((tfd = open("/dev/tty", O_RDWR, 0)) < 0) {
tty_devtty = false;
#ifndef MKSH_DISABLE_TTY_WARNING
if (need_tty)
warningf(false, "%s: %s %s: %s",
"No controlling tty", "open", "/dev/tty",
strerror(errno));
#endif
}
if (tfd < 0) {
do_close = false;
if (isatty(0))
tfd = 0;
else if (isatty(2))
tfd = 2;
else {
#ifndef MKSH_DISABLE_TTY_WARNING
if (need_tty)
warningf(false, "can't find tty fd");
#endif
return;
}
}
if ((tty_fd = fcntl(tfd, F_DUPFD, FDBASE)) < 0) {
if (need_tty)
warningf(false, "%s: %s %s: %s", "j_ttyinit",
"dup of tty fd", "failed", strerror(errno));
} else if (fcntl(tty_fd, F_SETFD, FD_CLOEXEC) < 0) {
if (need_tty)
warningf(false, "%s: %s: %s", "j_ttyinit",
"can't set close-on-exec flag", strerror(errno));
close(tty_fd);
tty_fd = -1;
} else if (init_ttystate)
mksh_tcget(tty_fd, &tty_state);
if (do_close)
close(tfd);
}
void
tty_close(void)
{
if (tty_fd >= 0) {
close(tty_fd);
tty_fd = -1;
}
}
/* A shell error occurred (eg, syntax error, etc.) */
#define VWARNINGF_ERRORPREFIX 1
#define VWARNINGF_FILELINE 2
#define VWARNINGF_BUILTIN 4
#define VWARNINGF_INTERNAL 8
static void vwarningf(unsigned int, const char *, va_list)
MKSH_A_FORMAT(__printf__, 2, 0);
static void
vwarningf(unsigned int flags, const char *fmt, va_list ap)
{
if (*fmt != 1) {
if (flags & VWARNINGF_INTERNAL)
shf_fprintf(shl_out, "internal error: ");
if (flags & VWARNINGF_ERRORPREFIX)
error_prefix(tobool(flags & VWARNINGF_FILELINE));
if ((flags & VWARNINGF_BUILTIN) &&
/* not set when main() calls parse_args() */
builtin_argv0 && builtin_argv0 != kshname)
shf_fprintf(shl_out, "%s: ", builtin_argv0);
shf_vfprintf(shl_out, fmt, ap);
shf_putchar('\n', shl_out);
}
shf_flush(shl_out);
}
void
errorfx(int rc, const char *fmt, ...)
{
va_list va;
exstat = rc;
/* debugging: note that stdout not valid */
shl_stdout_ok = false;
va_start(va, fmt);
vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
va_end(va);
unwind(LERROR);
}
void
errorf(const char *fmt, ...)
{
va_list va;
exstat = 1;
/* debugging: note that stdout not valid */
shl_stdout_ok = false;
va_start(va, fmt);
vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE, fmt, va);
va_end(va);
unwind(LERROR);
}
/* like errorf(), but no unwind is done */
void
warningf(bool fileline, const char *fmt, ...)
{
va_list va;
va_start(va, fmt);
vwarningf(VWARNINGF_ERRORPREFIX | (fileline ? VWARNINGF_FILELINE : 0),
fmt, va);
va_end(va);
}
/*
* Used by built-in utilities to prefix shell and utility name to message
* (also unwinds environments for special builtins).
*/
void
bi_errorf(const char *fmt, ...)
{
va_list va;
/* debugging: note that stdout not valid */
shl_stdout_ok = false;
exstat = 1;
va_start(va, fmt);
vwarningf(VWARNINGF_ERRORPREFIX | VWARNINGF_FILELINE |
VWARNINGF_BUILTIN, fmt, va);
va_end(va);
/*
* POSIX special builtins and ksh special builtins cause
* non-interactive shells to exit.
* XXX odd use of KEEPASN; also may not want LERROR here
*/
if (builtin_flag & SPEC_BI) {
builtin_argv0 = NULL;
unwind(LERROR);
}
}
/* Called when something that shouldn't happen does */
void
internal_errorf(const char *fmt, ...)
{
va_list va;
va_start(va, fmt);
vwarningf(VWARNINGF_INTERNAL, fmt, va);
va_end(va);
unwind(LERROR);
}
void
internal_warningf(const char *fmt, ...)
{
va_list va;
va_start(va, fmt);
vwarningf(VWARNINGF_INTERNAL, fmt, va);
va_end(va);
}
/* used by error reporting functions to print "ksh: .kshrc[25]: " */
void
error_prefix(bool fileline)
{
/* Avoid foo: foo[2]: ... */
if (!fileline || !source || !source->file ||
strcmp(source->file, kshname) != 0)
shf_fprintf(shl_out, "%s: ", kshname + (*kshname == '-'));
if (fileline && source && source->file != NULL) {
shf_fprintf(shl_out, "%s[%d]: ", source->file,
source->errline > 0 ? source->errline : source->line);
source->errline = 0;
}
}
/* printf to shl_out (stderr) with flush */
void
shellf(const char *fmt, ...)
{
va_list va;
if (!initio_done)
/* shl_out may not be set up yet... */
return;
va_start(va, fmt);
shf_vfprintf(shl_out, fmt, va);
va_end(va);
shf_flush(shl_out);
}
/* printf to shl_stdout (stdout) */
void
shprintf(const char *fmt, ...)
{
va_list va;
if (!shl_stdout_ok)
internal_errorf("shl_stdout not valid");
va_start(va, fmt);
shf_vfprintf(shl_stdout, fmt, va);
va_end(va);
}
/* test if we can seek backwards fd (returns 0 or SHF_UNBUF) */
int
can_seek(int fd)
{
struct stat statb;
return (fstat(fd, &statb) == 0 && !S_ISREG(statb.st_mode) ?
SHF_UNBUF : 0);
}
#ifdef DF
int shl_dbg_fd;
#define NSHF_IOB 4
#else
#define NSHF_IOB 3
#endif
struct shf shf_iob[NSHF_IOB];
void
initio(void)
{
/* force buffer allocation */
shf_fdopen(1, SHF_WR, shl_stdout);
shf_fdopen(2, SHF_WR, shl_out);
shf_fdopen(2, SHF_WR, shl_spare);
#ifdef DF
if ((shl_dbg_fd = open("/tmp/mksh-dbg.txt",
O_WRONLY | O_APPEND | O_CREAT, 0600)) == -1)
errorf("cannot open debug output file");
if (shl_dbg_fd < FDBASE) {
int nfd;
nfd = fcntl(shl_dbg_fd, F_DUPFD, FDBASE);
close(shl_dbg_fd);
if ((shl_dbg_fd = nfd) == -1)
errorf("cannot dup debug output file");
}
shf_fdopen(shl_dbg_fd, SHF_WR, shl_dbg);
DF("=== open ===");
#endif
initio_done = true;
}
/* A dup2() with error checking */
int
ksh_dup2(int ofd, int nfd, bool errok)
{
int rv;
if (((rv = dup2(ofd, nfd)) < 0) && !errok && (errno != EBADF))
errorf("too many files open in shell");
#ifdef __ultrix
/*XXX imake style */
if (rv >= 0)
fcntl(nfd, F_SETFD, 0);
#endif
return (rv);
}
/*
* Move fd from user space (0 <= fd < 10) to shell space (fd >= 10),
* set close-on-exec flag. See FDBASE in sh.h, maybe 24 not 10 here.
*/
short
savefd(int fd)
{
int nfd = fd;
if (fd < FDBASE && (nfd = fcntl(fd, F_DUPFD, FDBASE)) < 0 &&
errno == EBADF)
return (-1);
if (nfd < 0 || nfd > SHRT_MAX)
errorf("too many files open in shell");
fcntl(nfd, F_SETFD, FD_CLOEXEC);
return ((short)nfd);
}
void
restfd(int fd, int ofd)
{
if (fd == 2)
shf_flush(&shf_iob[fd]);
if (ofd < 0)
/* original fd closed */
close(fd);
else if (fd != ofd) {
/*XXX: what to do if this dup fails? */
ksh_dup2(ofd, fd, true);
close(ofd);
}
}
void
openpipe(int *pv)
{
int lpv[2];
if (pipe(lpv) < 0)
errorf("can't create pipe - try again");
pv[0] = savefd(lpv[0]);
if (pv[0] != lpv[0])
close(lpv[0]);
pv[1] = savefd(lpv[1]);
if (pv[1] != lpv[1])
close(lpv[1]);
}
void
closepipe(int *pv)
{
close(pv[0]);
close(pv[1]);
}
/*
* Called by iosetup() (deals with 2>&4, etc.), c_read, c_print to turn
* a string (the X in 2>&X, read -uX, print -uX) into a file descriptor.
*/
int
check_fd(const char *name, int mode, const char **emsgp)
{
int fd, fl;
if (name[0] == 'p' && !name[1])
return (coproc_getfd(mode, emsgp));
for (fd = 0; ksh_isdigit(*name); ++name)
fd = (fd * 10) + *name - '0';
if (*name || fd >= FDBASE) {
if (emsgp)
*emsgp = "illegal file descriptor name";
return (-1);
}
if ((fl = fcntl(fd, F_GETFL, 0)) < 0) {
if (emsgp)
*emsgp = "bad file descriptor";
return (-1);
}
fl &= O_ACCMODE;
/*
* X_OK is a kludge to disable this check for dups (x<&1):
* historical shells never did this check (XXX don't know what
* POSIX has to say).
*/
if (!(mode & X_OK) && fl != O_RDWR && (
((mode & R_OK) && fl != O_RDONLY) ||
((mode & W_OK) && fl != O_WRONLY))) {
if (emsgp)
*emsgp = (fl == O_WRONLY) ?
"fd not open for reading" :
"fd not open for writing";
return (-1);
}
return (fd);
}
/* Called once from main */
void
coproc_init(void)
{
coproc.read = coproc.readw = coproc.write = -1;
coproc.njobs = 0;
coproc.id = 0;
}
/* Called by c_read() when eof is read - close fd if it is the co-process fd */
void
coproc_read_close(int fd)
{
if (coproc.read >= 0 && fd == coproc.read) {
coproc_readw_close(fd);
close(coproc.read);
coproc.read = -1;
}
}
/*
* Called by c_read() and by iosetup() to close the other side of the
* read pipe, so reads will actually terminate.
*/
void
coproc_readw_close(int fd)
{
if (coproc.readw >= 0 && coproc.read >= 0 && fd == coproc.read) {
close(coproc.readw);
coproc.readw = -1;
}
}
/*
* Called by c_print when a write to a fd fails with EPIPE and by iosetup
* when co-process input is dup'd
*/
void
coproc_write_close(int fd)
{
if (coproc.write >= 0 && fd == coproc.write) {
close(coproc.write);
coproc.write = -1;
}
}
/*
* Called to check for existence of/value of the co-process file descriptor.
* (Used by check_fd() and by c_read/c_print to deal with -p option).
*/
int
coproc_getfd(int mode, const char **emsgp)
{
int fd = (mode & R_OK) ? coproc.read : coproc.write;
if (fd >= 0)
return (fd);
if (emsgp)
*emsgp = "no coprocess";
return (-1);
}
/*
* called to close file descriptors related to the coprocess (if any)
* Should be called with SIGCHLD blocked.
*/
void
coproc_cleanup(int reuse)
{
/* This to allow co-processes to share output pipe */
if (!reuse || coproc.readw < 0 || coproc.read < 0) {
if (coproc.read >= 0) {
close(coproc.read);
coproc.read = -1;
}
if (coproc.readw >= 0) {
close(coproc.readw);
coproc.readw = -1;
}
}
if (coproc.write >= 0) {
close(coproc.write);
coproc.write = -1;
}
}
struct temp *
maketemp(Area *ap, Temp_type type, struct temp **tlist)
{
char *cp;
size_t len;
int i;
struct temp *tp;
const char *dir;
struct stat sb;
dir = tmpdir ? tmpdir : MKSH_DEFAULT_TMPDIR;
/* add "/shXXXXXX.tmp" plus NUL */
len = strlen(dir);
checkoktoadd(len, offsetof(struct temp, tffn[0]) + 14);
tp = alloc(offsetof(struct temp, tffn[0]) + 14 + len, ap);
tp->shf = NULL;
tp->pid = procpid;
tp->type = type;
if (stat(dir, &sb) || !S_ISDIR(sb.st_mode)) {
tp->tffn[0] = '\0';
goto maketemp_out;
}
cp = (void *)tp;
cp += offsetof(struct temp, tffn[0]);
memcpy(cp, dir, len);
cp += len;
memcpy(cp, "/shXXXXXX.tmp", 14);
/* point to the first of six Xes */
cp += 3;
/* generate random part of filename */
len = -1;
do {
i = rndget() % 36;
cp[++len] = i < 26 ? 'a' + i : '0' + i - 26;
} while (len < 5);
/* cyclically attempt to open a temporary file */
while ((i = open(tp->tffn, O_CREAT | O_EXCL | O_RDWR, 0600)) == -1) {
if (errno != EEXIST)
goto maketemp_out;
/* count down from z to a then from 9 to 0 */
while (cp[len] == '0')
if (!len--)
goto maketemp_out;
if (cp[len] == 'a')
cp[len] = '9';
else
--cp[len];
/* do another cycle */
}
/* shf_fdopen cannot fail, so no fd leak */
tp->shf = shf_fdopen(i, SHF_WR, NULL);
maketemp_out:
tp->next = *tlist;
*tlist = tp;
return (tp);
}
/*
* We use a similar collision resolution algorithm as Python 2.5.4
* but with a slightly tweaked implementation written from scratch.
*/
#define INIT_TBLSHIFT 3 /* initial table shift (2^3 = 8) */
#define PERTURB_SHIFT 5 /* see Python 2.5.4 Objects/dictobject.c */
static void tgrow(struct table *);
static int tnamecmp(const void *, const void *);
static void
tgrow(struct table *tp)
{
size_t i, j, osize, mask, perturb;
struct tbl *tblp, **pp;
struct tbl **ntblp, **otblp = tp->tbls;
if (tp->tshift > 29)
internal_errorf("hash table size limit reached");
/* calculate old size, new shift and new size */
osize = (size_t)1 << (tp->tshift++);
i = osize << 1;
ntblp = alloc2(i, sizeof(struct tbl *), tp->areap);
/* multiplication cannot overflow: alloc2 checked that */
memset(ntblp, 0, i * sizeof(struct tbl *));
/* table can get very full when reaching its size limit */
tp->nfree = (tp->tshift == 30) ? 0x3FFF0000UL :
/* but otherwise, only 75% */
((i * 3) / 4);
tp->tbls = ntblp;
if (otblp == NULL)
return;
mask = i - 1;
for (i = 0; i < osize; i++)
if ((tblp = otblp[i]) != NULL) {
if ((tblp->flag & DEFINED)) {
/* search for free hash table slot */
j = (perturb = tblp->ua.hval) & mask;
goto find_first_empty_slot;
find_next_empty_slot:
j = (j << 2) + j + perturb + 1;
perturb >>= PERTURB_SHIFT;
find_first_empty_slot:
pp = &ntblp[j & mask];
if (*pp != NULL)
goto find_next_empty_slot;
/* found an empty hash table slot */
*pp = tblp;
tp->nfree--;
} else if (!(tblp->flag & FINUSE)) {
afree(tblp, tp->areap);
}
}
afree(otblp, tp->areap);
}
void
ktinit(Area *ap, struct table *tp, uint8_t initshift)
{
tp->areap = ap;
tp->tbls = NULL;
tp->tshift = ((initshift > INIT_TBLSHIFT) ?
initshift : INIT_TBLSHIFT) - 1;
tgrow(tp);
}
/* table, name (key) to search for, hash(name), rv pointer to tbl ptr */
struct tbl *
ktscan(struct table *tp, const char *name, uint32_t h, struct tbl ***ppp)
{
size_t j, perturb, mask;
struct tbl **pp, *p;
mask = ((size_t)1 << (tp->tshift)) - 1;
/* search for hash table slot matching name */
j = (perturb = h) & mask;
goto find_first_slot;
find_next_slot:
j = (j << 2) + j + perturb + 1;
perturb >>= PERTURB_SHIFT;
find_first_slot:
pp = &tp->tbls[j & mask];
if ((p = *pp) != NULL && (p->ua.hval != h || !(p->flag & DEFINED) ||
strcmp(p->name, name)))
goto find_next_slot;
/* p == NULL if not found, correct found entry otherwise */
if (ppp)
*ppp = pp;
return (p);
}
/* table, name (key) to enter, hash(n) */
struct tbl *
ktenter(struct table *tp, const char *n, uint32_t h)
{
struct tbl **pp, *p;
size_t len;
Search:
if ((p = ktscan(tp, n, h, &pp)))
return (p);
if (tp->nfree == 0) {
/* too full */
tgrow(tp);
goto Search;
}
/* create new tbl entry */
len = strlen(n);
checkoktoadd(len, offsetof(struct tbl, name[0]) + 1);
p = alloc(offsetof(struct tbl, name[0]) + ++len, tp->areap);
p->flag = 0;
p->type = 0;
p->areap = tp->areap;
p->ua.hval = h;
p->u2.field = 0;
p->u.array = NULL;
memcpy(p->name, n, len);
/* enter in tp->tbls */
tp->nfree--;
*pp = p;
return (p);
}
void
ktwalk(struct tstate *ts, struct table *tp)
{
ts->left = (size_t)1 << (tp->tshift);
ts->next = tp->tbls;
}
struct tbl *
ktnext(struct tstate *ts)
{
while (--ts->left >= 0) {
struct tbl *p = *ts->next++;
if (p != NULL && (p->flag & DEFINED))
return (p);
}
return (NULL);
}
static int
tnamecmp(const void *p1, const void *p2)
{
const struct tbl *a = *((const struct tbl * const *)p1);
const struct tbl *b = *((const struct tbl * const *)p2);
return (strcmp(a->name, b->name));
}
struct tbl **
ktsort(struct table *tp)
{
size_t i;
struct tbl **p, **sp, **dp;
/*
* since the table is never entirely full, no need to reserve
* additional space for the trailing NULL appended below
*/
i = (size_t)1 << (tp->tshift);
p = alloc2(i, sizeof(struct tbl *), ATEMP);
sp = tp->tbls; /* source */
dp = p; /* dest */
while (i--)
if ((*dp = *sp++) != NULL && (((*dp)->flag & DEFINED) ||
((*dp)->flag & ARRAY)))
dp++;
qsort(p, (i = dp - p), sizeof(struct tbl *), tnamecmp);
p[i] = NULL;
return (p);
}
#ifdef SIGWINCH
static void
x_sigwinch(int sig MKSH_A_UNUSED)
{
/* this runs inside interrupt context, with errno saved */
got_winch = 1;
}
#endif
#ifdef DF
void
DF(const char *fmt, ...)
{
va_list args;
struct timeval tv;
mksh_lockfd(shl_dbg_fd);
mksh_TIME(tv);
shf_fprintf(shl_dbg, "[%d.%06d:%d] ", (int)tv.tv_sec, (int)tv.tv_usec,
(int)getpid());
va_start(args, fmt);
shf_vfprintf(shl_dbg, fmt, args);
va_end(args);
shf_putc('\n', shl_dbg);
shf_flush(shl_dbg);
mksh_unlkfd(shl_dbg_fd);
}
#endif
void
x_mkraw(int fd, mksh_ttyst *ocb, bool forread)
{
mksh_ttyst cb;
if (ocb)
mksh_tcget(fd, ocb);
else
ocb = &tty_state;
cb = *ocb;
if (forread) {
cb.c_lflag &= ~(ICANON) | ECHO;
} else {
cb.c_iflag &= ~(INLCR | ICRNL);
cb.c_lflag &= ~(ISIG | ICANON | ECHO);
}
#if defined(VLNEXT) && defined(_POSIX_VDISABLE)
/* OSF/1 processes lnext when ~icanon */
cb.c_cc[VLNEXT] = _POSIX_VDISABLE;
#endif
/* SunOS 4.1.x & OSF/1 processes discard(flush) when ~icanon */
#if defined(VDISCARD) && defined(_POSIX_VDISABLE)
cb.c_cc[VDISCARD] = _POSIX_VDISABLE;
#endif
cb.c_cc[VTIME] = 0;
cb.c_cc[VMIN] = 1;
mksh_tcset(fd, &cb);
}