/* $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 * */ #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; } }