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mksh/histrap.c

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/* $OpenBSD: history.c,v 1.35 2006/05/29 18:22:24 otto 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 1.33 2006/11/10 07:52:02 tg Exp $");
#ifndef mksh_siglist
#if defined(BSD) || defined(__APPLE__)
#define mksh_signame(x) sys_signame[(x)]
#define mksh_siglist(x) sys_siglist[(x)]
#elif defined(__INTERIX)
#define mksh_signame(x) _sys_signame[(x)]
#define mksh_siglist(x) _sys_siglist[(x)]
#elif defined(__gnu_linux__) || defined(__sun__) || defined(__CYGWIN__)
#define NEED_MKSH_SIGNAME /* sync the list above with Build.sh */
#define mksh_siglist(x) strsignal(x)
#else
# error "Define sys_sig{name,list} for this platform!"
#endif
#endif /* ndef mksh_siglist */
Trap sigtraps[NSIG + 1];
static struct sigaction Sigact_ign, Sigact_trap;
#ifdef V_HISTFILE
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, unsigned 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;
#ifdef V_HISTFILE
static char *hname; /* current name of history file */
static int histfd;
static int hsize;
#endif
int
c_fc(char **wp)
{
struct shf *shf;
struct temp *tf = NULL;
char *p, *editor = NULL;
int gflag = 0, lflag = 0, nflag = 0, sflag = 0, rflag = 0;
int optc;
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 (strcmp(p, "-") == 0)
sflag++;
else {
size_t len = strlen(p);
editor = str_nsave(p, len + 4, ATEMP);
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 = strchr(*wp + 1, '='))) {
pat = str_save(*wp, ATEMP);
p = pat + (p - *wp);
*p++ = '\0';
rep = p;
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;
const char *nfmt = nflag ? "\t" : "%d\t";
for (hp = rflag ? hlast : hfirst;
hp >= hfirst && hp <= hlast; hp += rflag ? -1 : 1) {
shf_fprintf(shl_stdout, nfmt,
hist_source->line - (int) (histptr - hp));
/* print multi-line commands correctly */
for (s = *hp; (t = strchr(s, '\n')); s = t)
shf_fprintf(shl_stdout, "%.*s\t",
(int)(++t - s), s);
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, 1);
shellf("%s\n", p); /* POSIX doesn't say this is done... */
if ((p = 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)
line = str_save(*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 (hp < history) {
if (approx)
hp = hist_get_oldest();
else {
bi_errorf("%s: not in history", str);
hp = NULL;
}
} else if (hp > 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 */
n = findhist(histptr - history - 1, 0, str, anchored);
if (n < 0) {
bi_errorf("%s: not in history", str);
hp = NULL;
} 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;
}
if (allow_cur)
return histptr;
return 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((void*)*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 = (char **)aresize(history, n*sizeof(char *), APERM);
histsize = n;
histptr = history + cursize;
}
}
#ifdef V_HISTFILE
/*
* 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 = (char **)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 lno __attribute__((unused)), const char *cmd,
int dowrite __attribute__((unused)))
{
char **hp;
char *c, *cp;
c = str_save(cmd, APERM);
if ((cp = strchr(c, '\n')) != NULL)
*cp = '\0';
#ifdef V_HISTFILE
if (histfd && dowrite)
writehistfile(lno, c);
#endif
hp = histptr;
if (++hp >= history + histsize) { /* remove oldest command */
afree((void*)*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)
{
#ifdef V_HISTFILE
unsigned char *base;
int lines;
int fd;
#endif
if (Flag(FTALKING) == 0)
return;
hstarted = 1;
hist_source = s;
#ifdef V_HISTFILE
hname = str_val(global("HISTFILE"));
if (hname == NULL)
return;
hname = str_save(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 = (unsigned char *)mmap(0, hsize, PROT_READ,
MAP_FILE|MAP_PRIVATE, histfd, 0);
/*
* check on its validity
*/
if (base == MAP_FAILED || *base != HMAGIC1 || base[1] != HMAGIC2) {
if (base != MAP_FAILED)
munmap((caddr_t)base, hsize);
hist_finish();
unlink(hname);
goto retry;
}
if (hsize > 2) {
lines = hist_count_lines(base+2, hsize-2);
if (lines > histsize) {
/* we need to make the file smaller */
if (hist_shrink(base, hsize))
unlink(hname);
munmap((caddr_t)base, hsize);
hist_finish();
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
}
#ifdef V_HISTFILE
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
*/
(void) shf_snprintf(nfile, sizeof(nfile), "%s.%d", hname, 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);
if (sprinkle(fd)) {
close(fd);
unlink(nfile);
return 1;
}
if (write(fd, nbase, nbytes) != nbytes) {
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, line);
} else {
s->line = lno;
histsave(lno, (char *)line, 0);
}
state = shdr;
}
}
}
}
/*
* Insert a line into the history at a specified number
*/
static void
histinsert(Source *s, int lno, unsigned char *line)
{
char **hp;
if (lno >= s->line-(histptr-history) && lno <= s->line) {
hp = &histptr[lno-s->line];
if (*hp)
afree((void*)*hp, APERM);
*hp = str_save((char *)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 = (unsigned char *)mmap(0, sizenow,
PROT_READ, MAP_FILE|MAP_PRIVATE, histfd, 0);
if (base == 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;
(void) write(histfd, hdr, 5);
(void) write(histfd, cmd, strlen(cmd)+1);
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 unsigned char mag[] = { HMAGIC1, HMAGIC2 };
return(write(fd, mag, 2) != 2);
}
#endif
#ifdef NEED_MKSH_SIGNAME
static const char *
mksh_signame(int s)
{
int i = 0;
static const struct _mksh_sigpair {
int nr;
const char *name;
} mksh_sigpair[] = {
#include "signames.inc"
{ 0, NULL }
};
mksh_sigscan:
if ((mksh_sigpair[i].nr == s) || !mksh_sigpair[i].name)
return (mksh_sigpair[i].name);
++i;
goto mksh_sigscan;
}
#endif
void
inittraps(void)
{
int i;
/* 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 {
sigtraps[i].name = mksh_signame(i);
sigtraps[i].mess = mksh_siglist(i);
}
}
sigtraps[SIGEXIT_].name = "EXIT"; /* our name for signal 0 */
sigemptyset(&Sigact_ign.sa_mask);
Sigact_ign.sa_flags = 0; /* interruptible */
Sigact_ign.sa_handler = SIG_IGN;
Sigact_trap = Sigact_ign;
Sigact_trap.sa_handler = trapsig;
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 __attribute__((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 i;
Trap *p;
if (ksh_isdigit(*name)) {
int n;
if (getn(name, &n) && 0 <= n && n < NSIG)
return &sigtraps[n];
return NULL;
}
for (p = sigtraps, i = NSIG+1; --i >= 0; p++)
if (p->name) {
if (igncase) {
if (p->name && (!strcasecmp(p->name, name) ||
(strlen(name) > 3 &&
(p->name[0] == 's' || p->name[0] == 'S') &&
(p->name[1] == 'i' || p->name[1] == 'I') &&
(p->name[2] == 'g' || p->name[2] == 'G') &&
!strcasecmp(p->name, name + 3))))
return p;
} else {
if (p->name && (!strcmp(p->name, name) ||
(strlen(name) > 3 && !strncmp("SIG",
p->name, 3) && !strcmp(p->name, name + 3))))
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, char *s)
{
sig_t f;
if (p->trap)
afree(p->trap, APERM);
p->trap = str_save(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 = NULL;
if (flags & SS_SHTRAP) {
p->shtrap = f;
f = trapsig;
}
if (p->cursig != f) {
p->cursig = f;
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(1, "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;
}
}
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