/* $OpenBSD: history.c,v 1.51 2015/10/21 15:47:41 mmcc Exp $ */ /* * command history */ /* * This file contains * a) the original in-memory history mechanism * b) a more complicated mechanism done by pc@hillside.co.uk * that more closely follows the real ksh way of doing * things. You need to have the mmap system call for this * to work on your system */ #include #include #include "sh.h" #ifdef HISTORY # include /* * variables for handling the data file */ static int histfd; static int hsize; 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); 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 char *hname; /* current name of history file */ static int hstarted; /* set after hist_init() called */ static Source *hist_source; 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) + 4; editor = str_nsave(p, len, ATEMP); strlcat(editor, " $_", len); } 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", ++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} $_", 0); 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 = fstat(shf->fd, &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, 0); source = sold; return ret; } static int hist_replace(char **hp, const char *pat, const char *rep, int global) { 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 || global); 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 ((long)hp < (long)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 oldest 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 = atoi(str); 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; } } /* * 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); } /* * initialise the history vector */ void init_histvec(void) { if (history == 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 lno, const char *cmd, int dowrite) { char **hp; char *c, *cp; c = str_save(cmd, APERM); if ((cp = strchr(c, '\n')) != NULL) *cp = '\0'; if (histfd && dowrite) writehistfile(lno, c); 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 is still recorded, 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. */ /* * History file format: * Bytes 1, 2: HMAGIC - just to check that we are dealing with the correct object * Each command, in the format: */ #define HMAGIC1 0xab #define HMAGIC2 0xcd #define COMMAND 0xff void hist_init(Source *s) { unsigned char *base; int lines; int fd; struct stat sb; if (Flag(FTALKING) == 0) return; hstarted = 1; hist_source = s; 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; if (fstat(fd, &sb) == -1 || sb.st_uid != getuid()) { close(fd); 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 = 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(); if (unlink(hname) != 0) return; 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)) if (unlink(hname) != 0) return; 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); } 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[1024]; 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 (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; s->cmd_offset = 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]; afree(*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 = 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); } #else /* HISTORY */ /* No history to be compiled in: dummy routines to avoid lots more ifdefs */ void init_histvec(void) { } void hist_init(Source *s) { } void hist_finish(void) { } void histsave(int lno, const char *cmd, int dowrite) { errorf("history not enabled"); } #endif /* HISTORY */