mksh/histrap.c

1416 lines
30 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* $OpenBSD: history.c,v 1.36 2008/05/20 00:30:30 fgsch Exp $ */
/* $OpenBSD: trap.c,v 1.22 2005/03/30 17:16:37 deraadt Exp $ */
#include "sh.h"
__RCSID("$MirOS: src/bin/mksh/histrap.c,v 1.75 2008/11/12 00:54:48 tg Exp $");
/*-
* MirOS: This is the default mapping type, and need not be specified.
* IRIX doesnt have this constant.
*/
#ifndef MAP_FILE
#define MAP_FILE 0
#endif
Trap sigtraps[NSIG + 1];
static struct sigaction Sigact_ign;
#if HAVE_PERSISTENT_HISTORY
static int hist_count_lines(unsigned char *, int);
static int hist_shrink(unsigned char *, int);
static unsigned char *hist_skip_back(unsigned char *,int *,int);
static void histload(Source *, unsigned char *, int);
static void histinsert(Source *, int, const char *);
static void writehistfile(int, char *);
static int sprinkle(int);
#endif
static int hist_execute(char *);
static int hist_replace(char **, const char *, const char *, int);
static char **hist_get(const char *, int, int);
static char **hist_get_oldest(void);
static void histbackup(void);
static char **current; /* current position in history[] */
static int hstarted; /* set after hist_init() called */
static Source *hist_source;
#if HAVE_PERSISTENT_HISTORY
static char *hname; /* current name of history file */
static int histfd;
static int hsize;
#endif
int
c_fc(const char **wp)
{
struct shf *shf;
struct temp *tf;
const char *p;
char *editor = NULL;
int gflag = 0, lflag = 0, nflag = 0, sflag = 0, rflag = 0;
int optc;
const char *first = NULL, *last = NULL;
char **hfirst, **hlast, **hp;
if (!Flag(FTALKING_I)) {
bi_errorf("history functions not available");
return 1;
}
while ((optc = ksh_getopt(wp, &builtin_opt,
"e:glnrs0,1,2,3,4,5,6,7,8,9,")) != -1)
switch (optc) {
case 'e':
p = builtin_opt.optarg;
if (ksh_isdash(p))
sflag++;
else {
size_t len = strlen(p);
editor = alloc(1, len + 4, ATEMP);
memcpy(editor, p, len);
memcpy(editor + len, " $_", 4);
}
break;
case 'g': /* non-at&t ksh */
gflag++;
break;
case 'l':
lflag++;
break;
case 'n':
nflag++;
break;
case 'r':
rflag++;
break;
case 's': /* posix version of -e - */
sflag++;
break;
/* kludge city - accept -num as -- -num (kind of) */
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
p = shf_smprintf("-%c%s",
optc, builtin_opt.optarg);
if (!first)
first = p;
else if (!last)
last = p;
else {
bi_errorf("too many arguments");
return 1;
}
break;
case '?':
return 1;
}
wp += builtin_opt.optind;
/* Substitute and execute command */
if (sflag) {
char *pat = NULL, *rep = NULL;
if (editor || lflag || nflag || rflag) {
bi_errorf("can't use -e, -l, -n, -r with -s (-e -)");
return 1;
}
/* Check for pattern replacement argument */
if (*wp && **wp && (p = cstrchr(*wp + 1, '='))) {
strdupx(pat, *wp, ATEMP);
rep = pat + (p - *wp);
*rep++ = '\0';
wp++;
}
/* Check for search prefix */
if (!first && (first = *wp))
wp++;
if (last || *wp) {
bi_errorf("too many arguments");
return 1;
}
hp = first ? hist_get(first, false, false) :
hist_get_newest(false);
if (!hp)
return 1;
return hist_replace(hp, pat, rep, gflag);
}
if (editor && (lflag || nflag)) {
bi_errorf("can't use -l, -n with -e");
return 1;
}
if (!first && (first = *wp))
wp++;
if (!last && (last = *wp))
wp++;
if (*wp) {
bi_errorf("too many arguments");
return 1;
}
if (!first) {
hfirst = lflag ? hist_get("-16", true, true) :
hist_get_newest(false);
if (!hfirst)
return 1;
/* can't fail if hfirst didn't fail */
hlast = hist_get_newest(false);
} else {
/* POSIX says not an error if first/last out of bounds
* when range is specified; at&t ksh and pdksh allow out of
* bounds for -l as well.
*/
hfirst = hist_get(first, (lflag || last) ? true : false,
lflag ? true : false);
if (!hfirst)
return 1;
hlast = last ? hist_get(last, true, lflag ? true : false) :
(lflag ? hist_get_newest(false) : hfirst);
if (!hlast)
return 1;
}
if (hfirst > hlast) {
char **temp;
temp = hfirst; hfirst = hlast; hlast = temp;
rflag = !rflag; /* POSIX */
}
/* List history */
if (lflag) {
char *s, *t;
for (hp = rflag ? hlast : hfirst;
hp >= hfirst && hp <= hlast; hp += rflag ? -1 : 1) {
if (!nflag)
shf_fprintf(shl_stdout, "%d",
hist_source->line - (int)(histptr - hp));
shf_putc('\t', shl_stdout);
/* print multi-line commands correctly */
s = *hp;
while ((t = strchr(s, '\n'))) {
*t = '\0';
shf_fprintf(shl_stdout, "%s\n\t", s);
*t++ = '\n';
s = t;
}
shf_fprintf(shl_stdout, "%s\n", s);
}
shf_flush(shl_stdout);
return 0;
}
/* Run editor on selected lines, then run resulting commands */
tf = maketemp(ATEMP, TT_HIST_EDIT, &e->temps);
if (!(shf = tf->shf)) {
bi_errorf("cannot create temp file %s - %s",
tf->name, strerror(errno));
return 1;
}
for (hp = rflag ? hlast : hfirst;
hp >= hfirst && hp <= hlast; hp += rflag ? -1 : 1)
shf_fprintf(shf, "%s\n", *hp);
if (shf_close(shf) == EOF) {
bi_errorf("error writing temporary file - %s", strerror(errno));
return 1;
}
/* Ignore setstr errors here (arbitrary) */
setstr(local("_", false), tf->name, KSH_RETURN_ERROR);
/* XXX: source should not get trashed by this.. */
{
Source *sold = source;
int ret;
ret = command(editor ? editor : "${FCEDIT:-/bin/ed} $_");
source = sold;
if (ret)
return ret;
}
{
struct stat statb;
XString xs;
char *xp;
int n;
if (!(shf = shf_open(tf->name, O_RDONLY, 0, 0))) {
bi_errorf("cannot open temp file %s", tf->name);
return 1;
}
n = stat(tf->name, &statb) < 0 ? 128 : statb.st_size + 1;
Xinit(xs, xp, n, hist_source->areap);
while ((n = shf_read(xp, Xnleft(xs, xp), shf)) > 0) {
xp += n;
if (Xnleft(xs, xp) <= 0)
XcheckN(xs, xp, Xlength(xs, xp));
}
if (n < 0) {
bi_errorf("error reading temp file %s - %s",
tf->name, strerror(shf_errno(shf)));
shf_close(shf);
return 1;
}
shf_close(shf);
*xp = '\0';
strip_nuls(Xstring(xs, xp), Xlength(xs, xp));
return hist_execute(Xstring(xs, xp));
}
}
/* Save cmd in history, execute cmd (cmd gets trashed) */
static int
hist_execute(char *cmd)
{
Source *sold;
int ret;
char *p, *q;
histbackup();
for (p = cmd; p; p = q) {
if ((q = strchr(p, '\n'))) {
*q++ = '\0'; /* kill the newline */
if (!*q) /* ignore trailing newline */
q = NULL;
}
histsave(&hist_source->line, p, true, true);
shellf("%s\n", p); /* POSIX doesn't say this is done... */
if (q) /* restore \n (trailing \n not restored) */
q[-1] = '\n';
}
/* Commands are executed here instead of pushing them onto the
* input 'cause posix says the redirection and variable assignments
* in
* X=y fc -e - 42 2> /dev/null
* are to effect the repeated commands environment.
*/
/* XXX: source should not get trashed by this.. */
sold = source;
ret = command(cmd);
source = sold;
return ret;
}
static int
hist_replace(char **hp, const char *pat, const char *rep, int globr)
{
char *line;
if (!pat)
strdupx(line, *hp, ATEMP);
else {
char *s, *s1;
int pat_len = strlen(pat);
int rep_len = strlen(rep);
int len;
XString xs;
char *xp;
int any_subst = 0;
Xinit(xs, xp, 128, ATEMP);
for (s = *hp; (s1 = strstr(s, pat)) && (!any_subst || globr);
s = s1 + pat_len) {
any_subst = 1;
len = s1 - s;
XcheckN(xs, xp, len + rep_len);
memcpy(xp, s, len); /* first part */
xp += len;
memcpy(xp, rep, rep_len); /* replacement */
xp += rep_len;
}
if (!any_subst) {
bi_errorf("substitution failed");
return 1;
}
len = strlen(s) + 1;
XcheckN(xs, xp, len);
memcpy(xp, s, len);
xp += len;
line = Xclose(xs, xp);
}
return hist_execute(line);
}
/*
* get pointer to history given pattern
* pattern is a number or string
*/
static char **
hist_get(const char *str, int approx, int allow_cur)
{
char **hp = NULL;
int n;
if (getn(str, &n)) {
hp = histptr + (n < 0 ? n : (n - hist_source->line));
if ((ptrdiff_t)hp < (ptrdiff_t)history) {
if (approx)
hp = hist_get_oldest();
else {
bi_errorf("%s: not in history", str);
hp = NULL;
}
} else if ((ptrdiff_t)hp > (ptrdiff_t)histptr) {
if (approx)
hp = hist_get_newest(allow_cur);
else {
bi_errorf("%s: not in history", str);
hp = NULL;
}
} else if (!allow_cur && hp == histptr) {
bi_errorf("%s: invalid range", str);
hp = NULL;
}
} else {
int anchored = *str == '?' ? (++str, 0) : 1;
/* the -1 is to avoid the current fc command */
if ((n = findhist(histptr - history - 1, 0, str, anchored)) < 0)
bi_errorf("%s: not in history", str);
else
hp = &history[n];
}
return hp;
}
/* Return a pointer to the newest command in the history */
char **
hist_get_newest(int allow_cur)
{
if (histptr < history || (!allow_cur && histptr == history)) {
bi_errorf("no history (yet)");
return NULL;
}
return (allow_cur ? histptr : histptr - 1);
}
/* Return a pointer to the newest command in the history */
static char **
hist_get_oldest(void)
{
if (histptr <= history) {
bi_errorf("no history (yet)");
return NULL;
}
return history;
}
/******************************/
/* Back up over last histsave */
/******************************/
static void
histbackup(void)
{
static int last_line = -1;
if (histptr >= history && last_line != hist_source->line) {
hist_source->line--;
afree(*histptr, APERM);
histptr--;
last_line = hist_source->line;
}
}
/*
* Return the current position.
*/
char **
histpos(void)
{
return current;
}
int
histnum(int n)
{
int last = histptr - history;
if (n < 0 || n >= last) {
current = histptr;
return last;
} else {
current = &history[n];
return n;
}
}
/*
* This will become unnecessary if hist_get is modified to allow
* searching from positions other than the end, and in either
* direction.
*/
int
findhist(int start, int fwd, const char *str, int anchored)
{
char **hp;
int maxhist = histptr - history;
int incr = fwd ? 1 : -1;
int len = strlen(str);
if (start < 0 || start >= maxhist)
start = maxhist;
hp = &history[start];
for (; hp >= history && hp <= histptr; hp += incr)
if ((anchored && strncmp(*hp, str, len) == 0) ||
(!anchored && strstr(*hp, str)))
return hp - history;
return -1;
}
int
findhistrel(const char *str)
{
int maxhist = histptr - history;
int start = maxhist - 1;
int rec;
getn(str, &rec);
if (rec == 0)
return -1;
if (rec > 0) {
if (rec > maxhist)
return -1;
return rec - 1;
}
if (rec > maxhist)
return -1;
return start + rec + 1;
}
/*
* set history
* this means reallocating the dataspace
*/
void
sethistsize(int n)
{
if (n > 0 && n != histsize) {
int cursize = histptr - history;
/* save most recent history */
if (n < cursize) {
memmove(history, histptr - n, n * sizeof(char *));
cursize = n;
}
history = aresize(history, n, sizeof (char *), APERM);
histsize = n;
histptr = history + cursize;
}
}
#if HAVE_PERSISTENT_HISTORY
/*
* set history file
* This can mean reloading/resetting/starting history file
* maintenance
*/
void
sethistfile(const char *name)
{
/* if not started then nothing to do */
if (hstarted == 0)
return;
/* if the name is the same as the name we have */
if (hname && strcmp(hname, name) == 0)
return;
/*
* its a new name - possibly
*/
if (histfd) {
/* yes the file is open */
(void) close(histfd);
histfd = 0;
hsize = 0;
afree(hname, APERM);
hname = NULL;
/* let's reset the history */
histptr = history - 1;
hist_source->line = 0;
}
hist_init(hist_source);
}
#endif
/*
* initialise the history vector
*/
void
init_histvec(void)
{
if (history == (char **)NULL) {
histsize = HISTORYSIZE;
history = alloc(histsize, sizeof (char *), APERM);
histptr = history - 1;
}
}
/*
* Routines added by Peter Collinson BSDI(Europe)/Hillside Systems to
* a) permit HISTSIZE to control number of lines of history stored
* b) maintain a physical history file
*
* It turns out that there is a lot of ghastly hackery here
*/
/*
* save command in history
*/
void
histsave(int *lnp, const char *cmd, bool dowrite __unused, bool ignoredups)
{
char **hp;
char *c, *cp;
strdupx(c, cmd, APERM);
if ((cp = strchr(c, '\n')) != NULL)
*cp = '\0';
if (ignoredups && !strcmp(c, *histptr)) {
afree(c, APERM);
return;
}
++*lnp;
#if HAVE_PERSISTENT_HISTORY
if (histfd && dowrite)
writehistfile(*lnp, c);
#endif
hp = histptr;
if (++hp >= history + histsize) { /* remove oldest command */
afree(*history, APERM);
for (hp = history; hp < history + histsize - 1; hp++)
hp[0] = hp[1];
}
*hp = c;
histptr = hp;
}
/*
* Write history data to a file nominated by HISTFILE
* if HISTFILE is unset then history still happens, but
* the data is not written to a file
* All copies of ksh looking at the file will maintain the
* same history. This is ksh behaviour.
*
* This stuff uses mmap()
* if your system ain't got it - then you'll have to undef HISTORYFILE
*/
/*
* Open a history file
* Format is:
* Bytes 1, 2: HMAGIC - just to check that we are dealing with
* the correct object
* Then follows a number of stored commands
* Each command is
* <command byte><command number(4 bytes)><bytes><null>
*/
#define HMAGIC1 0xab
#define HMAGIC2 0xcd
#define COMMAND 0xff
void
hist_init(Source *s)
{
#if HAVE_PERSISTENT_HISTORY
unsigned char *base;
int lines;
int fd;
#endif
if (Flag(FTALKING) == 0)
return;
hstarted = 1;
hist_source = s;
#if HAVE_PERSISTENT_HISTORY
if ((hname = str_val(global("HISTFILE"))) == NULL)
return;
strdupx(hname, hname, APERM);
retry:
/* we have a file and are interactive */
if ((fd = open(hname, O_RDWR|O_CREAT|O_APPEND, 0600)) < 0)
return;
histfd = savefd(fd);
if (histfd != fd)
close(fd);
(void) flock(histfd, LOCK_EX);
hsize = lseek(histfd, 0L, SEEK_END);
if (hsize == 0) {
/* add magic */
if (sprinkle(histfd)) {
hist_finish();
return;
}
} else if (hsize > 0) {
/*
* we have some data
*/
base = (void *)mmap(NULL, hsize, PROT_READ,
MAP_FILE | MAP_PRIVATE, histfd, 0);
/*
* check on its validity
*/
if (base == (unsigned char *)MAP_FAILED ||
*base != HMAGIC1 || base[1] != HMAGIC2) {
if (base != (unsigned char *)MAP_FAILED)
munmap((caddr_t)base, hsize);
hist_finish();
if (unlink(hname) /* fails */)
goto hiniterr;
goto retry;
}
if (hsize > 2) {
int rv = 0;
lines = hist_count_lines(base+2, hsize-2);
if (lines > histsize) {
/* we need to make the file smaller */
if (hist_shrink(base, hsize))
rv = unlink(hname);
munmap((caddr_t)base, hsize);
hist_finish();
if (rv) {
hiniterr:
bi_errorf("cannot unlink HISTFILE %s"
" - %s", hname, strerror(errno));
hsize = 0;
return;
}
goto retry;
}
}
histload(hist_source, base+2, hsize-2);
munmap((caddr_t)base, hsize);
}
(void) flock(histfd, LOCK_UN);
hsize = lseek(histfd, 0L, SEEK_END);
#endif
}
#if HAVE_PERSISTENT_HISTORY
typedef enum state {
shdr, /* expecting a header */
sline, /* looking for a null byte to end the line */
sn1, /* bytes 1 to 4 of a line no */
sn2, sn3, sn4
} State;
static int
hist_count_lines(unsigned char *base, int bytes)
{
State state = shdr;
int lines = 0;
while (bytes--) {
switch (state) {
case shdr:
if (*base == COMMAND)
state = sn1;
break;
case sn1:
state = sn2; break;
case sn2:
state = sn3; break;
case sn3:
state = sn4; break;
case sn4:
state = sline; break;
case sline:
if (*base == '\0')
lines++, state = shdr;
}
base++;
}
return lines;
}
/*
* Shrink the history file to histsize lines
*/
static int
hist_shrink(unsigned char *oldbase, int oldbytes)
{
int fd;
char nfile[PATH_MAX];
struct stat statb;
unsigned char *nbase = oldbase;
int nbytes = oldbytes;
nbase = hist_skip_back(nbase, &nbytes, histsize);
if (nbase == NULL)
return 1;
if (nbase == oldbase)
return 0;
/*
* create temp file
*/
shf_snprintf(nfile, sizeof(nfile), "%s.%d", hname, (int)procpid);
if ((fd = open(nfile, O_CREAT | O_TRUNC | O_WRONLY, 0600)) < 0)
return 1;
if (fstat(histfd, &statb) >= 0 &&
chown(nfile, statb.st_uid, statb.st_gid))
goto errout;
if (sprinkle(fd) || write(fd, nbase, nbytes) != nbytes) {
errout:
close(fd);
unlink(nfile);
return 1;
}
close(fd);
/*
* rename
*/
if (rename(nfile, hname) < 0)
return 1;
return 0;
}
/*
* find a pointer to the data 'no' back from the end of the file
* return the pointer and the number of bytes left
*/
static unsigned char *
hist_skip_back(unsigned char *base, int *bytes, int no)
{
int lines = 0;
unsigned char *ep;
for (ep = base + *bytes; --ep > base; ) {
/* this doesn't really work: the 4 byte line number that is
* encoded after the COMMAND byte can itself contain the
* COMMAND byte....
*/
for (; ep > base && *ep != COMMAND; ep--)
;
if (ep == base)
break;
if (++lines == no) {
*bytes = *bytes - ((char *)ep - (char *)base);
return ep;
}
}
return NULL;
}
/*
* load the history structure from the stored data
*/
static void
histload(Source *s, unsigned char *base, int bytes)
{
State state;
int lno = 0;
unsigned char *line = NULL;
for (state = shdr; bytes-- > 0; base++) {
switch (state) {
case shdr:
if (*base == COMMAND)
state = sn1;
break;
case sn1:
lno = (((*base)&0xff)<<24);
state = sn2;
break;
case sn2:
lno |= (((*base)&0xff)<<16);
state = sn3;
break;
case sn3:
lno |= (((*base)&0xff)<<8);
state = sn4;
break;
case sn4:
lno |= (*base)&0xff;
line = base+1;
state = sline;
break;
case sline:
if (*base == '\0') {
/* worry about line numbers */
if (histptr >= history && lno-1 != s->line) {
/* a replacement ? */
histinsert(s, lno, (char *)line);
} else {
s->line = lno--;
histsave(&lno, (char *)line, false,
false);
}
state = shdr;
}
}
}
}
/*
* Insert a line into the history at a specified number
*/
static void
histinsert(Source *s, int lno, const char *line)
{
char **hp;
if (lno >= s->line - (histptr - history) && lno <= s->line) {
hp = &histptr[lno - s->line];
if (*hp)
afree(*hp, APERM);
strdupx(*hp, line, APERM);
}
}
/*
* write a command to the end of the history file
* This *MAY* seem easy but it's also necessary to check
* that the history file has not changed in size.
* If it has - then some other shell has written to it
* and we should read those commands to update our history
*/
static void
writehistfile(int lno, char *cmd)
{
int sizenow;
unsigned char *base;
unsigned char *new;
int bytes;
unsigned char hdr[5];
(void) flock(histfd, LOCK_EX);
sizenow = lseek(histfd, 0L, SEEK_END);
if (sizenow != hsize) {
/*
* Things have changed
*/
if (sizenow > hsize) {
/* someone has added some lines */
bytes = sizenow - hsize;
base = (void *)mmap(NULL, sizenow, PROT_READ,
MAP_FILE | MAP_PRIVATE, histfd, 0);
if (base == (unsigned char *)MAP_FAILED)
goto bad;
new = base + hsize;
if (*new != COMMAND) {
munmap((caddr_t)base, sizenow);
goto bad;
}
hist_source->line--;
histload(hist_source, new, bytes);
hist_source->line++;
lno = hist_source->line;
munmap((caddr_t)base, sizenow);
hsize = sizenow;
} else {
/* it has shrunk */
/* but to what? */
/* we'll give up for now */
goto bad;
}
}
/*
* we can write our bit now
*/
hdr[0] = COMMAND;
hdr[1] = (lno>>24)&0xff;
hdr[2] = (lno>>16)&0xff;
hdr[3] = (lno>>8)&0xff;
hdr[4] = lno&0xff;
bytes = strlen(cmd) + 1;
if ((write(histfd, hdr, 5) != 5) ||
(write(histfd, cmd, bytes) != bytes))
goto bad;
hsize = lseek(histfd, 0L, SEEK_END);
(void) flock(histfd, LOCK_UN);
return;
bad:
hist_finish();
}
void
hist_finish(void)
{
(void) flock(histfd, LOCK_UN);
(void) close(histfd);
histfd = 0;
}
/*
* add magic to the history file
*/
static int
sprinkle(int fd)
{
static const unsigned char mag[] = { HMAGIC1, HMAGIC2 };
return(write(fd, mag, 2) != 2);
}
#endif
#if !HAVE_SYS_SIGNAME
static const struct mksh_sigpair {
int nr;
const char *const name;
} mksh_sigpairs[] = {
#include "signames.inc"
{ 0, NULL }
};
#endif
void
inittraps(void)
{
int i;
const char *cs;
/* Populate sigtraps based on sys_signame and sys_siglist. */
for (i = 0; i <= NSIG; i++) {
sigtraps[i].signal = i;
if (i == SIGERR_) {
sigtraps[i].name = "ERR";
sigtraps[i].mess = "Error handler";
} else {
#if HAVE_SYS_SIGNAME
cs = sys_signame[i];
#else
const struct mksh_sigpair *pair = mksh_sigpairs;
while ((pair->nr != i) && (pair->name != NULL))
++pair;
cs = pair->name;
#endif
if ((cs == NULL) ||
(cs[0] == '\0'))
sigtraps[i].name = shf_smprintf("%d", i);
else {
char *s;
if (!strncasecmp(cs, "SIG", 3))
cs += 3;
strdupx(s, cs, APERM);
sigtraps[i].name = s;
while ((*s = ksh_toupper(*s)))
++s;
}
#if HAVE_SYS_SIGLIST
sigtraps[i].mess = sys_siglist[i];
#elif HAVE_STRSIGNAL
sigtraps[i].mess = strsignal(i);
#else
sigtraps[i].mess = NULL;
#endif
if ((sigtraps[i].mess == NULL) ||
(sigtraps[i].mess[0] == '\0'))
sigtraps[i].mess = shf_smprintf("Signal %d", i);
}
}
sigtraps[SIGEXIT_].name = "EXIT"; /* our name for signal 0 */
(void)sigemptyset(&Sigact_ign.sa_mask);
Sigact_ign.sa_flags = 0; /* interruptible */
Sigact_ign.sa_handler = SIG_IGN;
sigtraps[SIGINT].flags |= TF_DFL_INTR | TF_TTY_INTR;
sigtraps[SIGQUIT].flags |= TF_DFL_INTR | TF_TTY_INTR;
sigtraps[SIGTERM].flags |= TF_DFL_INTR;/* not fatal for interactive */
sigtraps[SIGHUP].flags |= TF_FATAL;
sigtraps[SIGCHLD].flags |= TF_SHELL_USES;
/* these are always caught so we can clean up any temporary files. */
setsig(&sigtraps[SIGINT], trapsig, SS_RESTORE_ORIG);
setsig(&sigtraps[SIGQUIT], trapsig, SS_RESTORE_ORIG);
setsig(&sigtraps[SIGTERM], trapsig, SS_RESTORE_ORIG);
setsig(&sigtraps[SIGHUP], trapsig, SS_RESTORE_ORIG);
}
static void alarm_catcher(int sig);
void
alarm_init(void)
{
sigtraps[SIGALRM].flags |= TF_SHELL_USES;
setsig(&sigtraps[SIGALRM], alarm_catcher,
SS_RESTORE_ORIG|SS_FORCE|SS_SHTRAP);
}
/* ARGSUSED */
static void
alarm_catcher(int sig __unused)
{
int errno_ = errno;
if (ksh_tmout_state == TMOUT_READING) {
int left = alarm(0);
if (left == 0) {
ksh_tmout_state = TMOUT_LEAVING;
intrsig = 1;
} else
alarm(left);
}
errno = errno_;
}
Trap *
gettrap(const char *name, int igncase)
{
int n = NSIG + 1;
Trap *p;
const char *n2;
int (*cmpfunc)(const char *, const char *) = strcmp;
if (ksh_isdigit(*name)) {
if (getn(name, &n) && 0 <= n && n < NSIG)
return (&sigtraps[n]);
else
return (NULL);
}
n2 = strncasecmp(name, "SIG", 3) ? NULL : name + 3;
if (igncase)
cmpfunc = strcasecmp;
for (p = sigtraps; --n >= 0; p++)
if (!cmpfunc(p->name, name) || (n2 && !cmpfunc(p->name, n2)))
return (p);
return (NULL);
}
/*
* trap signal handler
*/
void
trapsig(int i)
{
Trap *p = &sigtraps[i];
int errno_ = errno;
trap = p->set = 1;
if (p->flags & TF_DFL_INTR)
intrsig = 1;
if ((p->flags & TF_FATAL) && !p->trap) {
fatal_trap = 1;
intrsig = 1;
}
if (p->shtrap)
(*p->shtrap)(i);
errno = errno_;
}
/* called when we want to allow the user to ^C out of something - won't
* work if user has trapped SIGINT.
*/
void
intrcheck(void)
{
if (intrsig)
runtraps(TF_DFL_INTR|TF_FATAL);
}
/* called after EINTR to check if a signal with normally causes process
* termination has been received.
*/
int
fatal_trap_check(void)
{
int i;
Trap *p;
/* todo: should check if signal is fatal, not the TF_DFL_INTR flag */
for (p = sigtraps, i = NSIG+1; --i >= 0; p++)
if (p->set && (p->flags & (TF_DFL_INTR|TF_FATAL)))
/* return value is used as an exit code */
return 128 + p->signal;
return 0;
}
/* Returns the signal number of any pending traps: ie, a signal which has
* occurred for which a trap has been set or for which the TF_DFL_INTR flag
* is set.
*/
int
trap_pending(void)
{
int i;
Trap *p;
for (p = sigtraps, i = NSIG+1; --i >= 0; p++)
if (p->set && ((p->trap && p->trap[0]) ||
((p->flags & (TF_DFL_INTR|TF_FATAL)) && !p->trap)))
return p->signal;
return 0;
}
/*
* run any pending traps. If intr is set, only run traps that
* can interrupt commands.
*/
void
runtraps(int flag)
{
int i;
Trap *p;
if (ksh_tmout_state == TMOUT_LEAVING) {
ksh_tmout_state = TMOUT_EXECUTING;
warningf(false, "timed out waiting for input");
unwind(LEXIT);
} else
/* XXX: this means the alarm will have no effect if a trap
* is caught after the alarm() was started...not good.
*/
ksh_tmout_state = TMOUT_EXECUTING;
if (!flag)
trap = 0;
if (flag & TF_DFL_INTR)
intrsig = 0;
if (flag & TF_FATAL)
fatal_trap = 0;
for (p = sigtraps, i = NSIG+1; --i >= 0; p++)
if (p->set && (!flag ||
((p->flags & flag) && p->trap == NULL)))
runtrap(p);
}
void
runtrap(Trap *p)
{
int i = p->signal;
char *trapstr = p->trap;
int oexstat;
int old_changed = 0;
p->set = 0;
if (trapstr == NULL) { /* SIG_DFL */
if (p->flags & TF_FATAL) {
/* eg, SIGHUP */
exstat = 128 + i;
unwind(LLEAVE);
}
if (p->flags & TF_DFL_INTR) {
/* eg, SIGINT, SIGQUIT, SIGTERM, etc. */
exstat = 128 + i;
unwind(LINTR);
}
return;
}
if (trapstr[0] == '\0') /* SIG_IGN */
return;
if (i == SIGEXIT_ || i == SIGERR_) { /* avoid recursion on these */
old_changed = p->flags & TF_CHANGED;
p->flags &= ~TF_CHANGED;
p->trap = NULL;
}
oexstat = exstat;
/* Note: trapstr is fully parsed before anything is executed, thus
* no problem with afree(p->trap) in settrap() while still in use.
*/
command(trapstr);
exstat = oexstat;
if (i == SIGEXIT_ || i == SIGERR_) {
if (p->flags & TF_CHANGED)
/* don't clear TF_CHANGED */
afree(trapstr, APERM);
else
p->trap = trapstr;
p->flags |= old_changed;
}
}
/* clear pending traps and reset user's trap handlers; used after fork(2) */
void
cleartraps(void)
{
int i;
Trap *p;
trap = 0;
intrsig = 0;
fatal_trap = 0;
for (i = NSIG+1, p = sigtraps; --i >= 0; p++) {
p->set = 0;
if ((p->flags & TF_USER_SET) && (p->trap && p->trap[0]))
settrap(p, NULL);
}
}
/* restore signals just before an exec(2) */
void
restoresigs(void)
{
int i;
Trap *p;
for (i = NSIG+1, p = sigtraps; --i >= 0; p++)
if (p->flags & (TF_EXEC_IGN|TF_EXEC_DFL))
setsig(p, (p->flags & TF_EXEC_IGN) ? SIG_IGN : SIG_DFL,
SS_RESTORE_CURR|SS_FORCE);
}
void
settrap(Trap *p, const char *s)
{
sig_t f;
if (p->trap)
afree(p->trap, APERM);
strdupx(p->trap, s, APERM); /* handles s == 0 */
p->flags |= TF_CHANGED;
f = !s ? SIG_DFL : s[0] ? trapsig : SIG_IGN;
p->flags |= TF_USER_SET;
if ((p->flags & (TF_DFL_INTR|TF_FATAL)) && f == SIG_DFL)
f = trapsig;
else if (p->flags & TF_SHELL_USES) {
if (!(p->flags & TF_ORIG_IGN) || Flag(FTALKING)) {
/* do what user wants at exec time */
p->flags &= ~(TF_EXEC_IGN|TF_EXEC_DFL);
if (f == SIG_IGN)
p->flags |= TF_EXEC_IGN;
else
p->flags |= TF_EXEC_DFL;
}
/* assumes handler already set to what shell wants it
* (normally trapsig, but could be j_sigchld() or SIG_IGN)
*/
return;
}
/* todo: should we let user know signal is ignored? how? */
setsig(p, f, SS_RESTORE_CURR|SS_USER);
}
/* Called by c_print() when writing to a co-process to ensure SIGPIPE won't
* kill shell (unless user catches it and exits)
*/
int
block_pipe(void)
{
int restore_dfl = 0;
Trap *p = &sigtraps[SIGPIPE];
if (!(p->flags & (TF_ORIG_IGN|TF_ORIG_DFL))) {
setsig(p, SIG_IGN, SS_RESTORE_CURR);
if (p->flags & TF_ORIG_DFL)
restore_dfl = 1;
} else if (p->cursig == SIG_DFL) {
setsig(p, SIG_IGN, SS_RESTORE_CURR);
restore_dfl = 1; /* restore to SIG_DFL */
}
return restore_dfl;
}
/* Called by c_print() to undo whatever block_pipe() did */
void
restore_pipe(int restore_dfl)
{
if (restore_dfl)
setsig(&sigtraps[SIGPIPE], SIG_DFL, SS_RESTORE_CURR);
}
/* Set action for a signal. Action may not be set if original
* action was SIG_IGN, depending on the value of flags and FTALKING.
*/
int
setsig(Trap *p, sig_t f, int flags)
{
struct sigaction sigact;
if (p->signal == SIGEXIT_ || p->signal == SIGERR_)
return 1;
/* First time setting this signal? If so, get and note the current
* setting.
*/
if (!(p->flags & (TF_ORIG_IGN|TF_ORIG_DFL))) {
sigaction(p->signal, &Sigact_ign, &sigact);
p->flags |= sigact.sa_handler == SIG_IGN ?
TF_ORIG_IGN : TF_ORIG_DFL;
p->cursig = SIG_IGN;
}
/* Generally, an ignored signal stays ignored, except if
* - the user of an interactive shell wants to change it
* - the shell wants for force a change
*/
if ((p->flags & TF_ORIG_IGN) && !(flags & SS_FORCE) &&
(!(flags & SS_USER) || !Flag(FTALKING)))
return 0;
setexecsig(p, flags & SS_RESTORE_MASK);
/* This is here 'cause there should be a way of clearing shtraps, but
* don't know if this is a sane way of doing it. At the moment,
* all users of shtrap are lifetime users (SIGCHLD, SIGALRM, SIGWINCH).
*/
if (!(flags & SS_USER))
p->shtrap = (sig_t)NULL;
if (flags & SS_SHTRAP) {
p->shtrap = f;
f = trapsig;
}
if (p->cursig != f) {
p->cursig = f;
(void)sigemptyset(&sigact.sa_mask);
sigact.sa_flags = 0 /* interruptible */;
sigact.sa_handler = f;
sigaction(p->signal, &sigact, NULL);
}
return 1;
}
/* control what signal is set to before an exec() */
void
setexecsig(Trap *p, int restore)
{
/* XXX debugging */
if (!(p->flags & (TF_ORIG_IGN|TF_ORIG_DFL)))
internal_errorf("setexecsig: unset signal %d(%s)",
p->signal, p->name);
/* restore original value for exec'd kids */
p->flags &= ~(TF_EXEC_IGN|TF_EXEC_DFL);
switch (restore & SS_RESTORE_MASK) {
case SS_RESTORE_CURR: /* leave things as they currently are */
break;
case SS_RESTORE_ORIG:
p->flags |= p->flags & TF_ORIG_IGN ? TF_EXEC_IGN : TF_EXEC_DFL;
break;
case SS_RESTORE_DFL:
p->flags |= TF_EXEC_DFL;
break;
case SS_RESTORE_IGN:
p->flags |= TF_EXEC_IGN;
break;
}
}