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Diffstat (limited to 'history.c')
| -rw-r--r-- | history.c | 1207 |
1 files changed, 1207 insertions, 0 deletions
diff --git a/history.c b/history.c new file mode 100644 index 0000000..127c882 --- /dev/null +++ b/history.c @@ -0,0 +1,1207 @@ +/* $NetBSD: history.c,v 1.19 2018/05/08 16:37:59 kamil Exp $ */ + +/* + * command history + * + * only implements in-memory history. + */ + +/* + * This file contains + * a) the original in-memory history mechanism + * b) a simple file saving history mechanism done by sjg@zen + * define EASY_HISTORY to get this + * c) 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 <sys/cdefs.h> + +#ifndef lint +__RCSID("$NetBSD: history.c,v 1.19 2018/05/08 16:37:59 kamil Exp $"); +#endif + +#include <sys/stat.h> + +#include "sh.h" + +#ifdef HISTORY +# ifdef EASY_HISTORY + +# ifndef HISTFILE +# define HISTFILE ".pdksh_history" +# endif + +# else +/* Defines and includes for the complicated case */ + +# include <sys/file.h> +# include <sys/mman.h> + +/* + * variables for handling the data file + */ +static int histfd; +static int hsize; + +static int hist_count_lines ARGS((unsigned char *, int)); +static int hist_shrink ARGS((unsigned char *, int)); +static unsigned char *hist_skip_back ARGS((unsigned char *,int *,int)); +static void histload ARGS((Source *, unsigned char *, int)); +static void histinsert ARGS((Source *, int, unsigned char *)); +static void writehistfile ARGS((int, char *)); +static int sprinkle ARGS((int)); + +# ifdef MAP_FILE +# define MAP_FLAGS (MAP_FILE|MAP_PRIVATE) +# else +# define MAP_FLAGS MAP_PRIVATE +# endif + +# endif /* of EASY_HISTORY */ + +static int hist_execute ARGS((char *)); +static int hist_replace ARGS((char **, const char *, const char *, int)); +static char **hist_get ARGS((const char *, int, int)); +static char **hist_get_newest ARGS((int)); +static char **hist_get_oldest ARGS((void)); +static void histbackup ARGS((void)); + +static char **current; /* current position in history[] */ +static int curpos; /* current index 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(wp) + char **wp; +{ + struct shf *shf; + struct temp UNINITIALIZED(*tf); + char *p, *editor = (char *) 0; + int gflag = 0, lflag = 0, nflag = 0, sflag = 0, rflag = 0; + int optc; + char *first = (char *) 0, *last = (char *) 0; + char **hfirst, **hlast, **hp; + + if (hist_source == NULL) { + bi_errorf("not interactive"); + return 1; + } + + while ((optc = ksh_getopt(wp, &builtin_opt, "e:glnrs0,1,2,3,4,5,6,7,8,9,")) != EOF) + 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 = (char *) 0, *rep = (char *) 0; + + 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} $_"); + 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_fileno(shf), &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(cmd) + 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 = (char *) 0; + } +#ifdef EASY_HISTORY + if (p != cmd) + histappend(p, true); + else +#endif /* EASY_HISTORY */ + 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(hp, pat, rep, globalv) + char **hp; + const char *pat; + const char *rep; + int globalv; +{ + 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 || globalv) ; 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(str, approx, allow_cur) + const char *str; + int approx; + int allow_cur; +{ + char **hp = (char **) 0; + int n; + + if (getn(str, &n)) { + hp = histptr + (n < 0 ? n : (n - hist_source->line)); + if (hp < histlist) { + if (approx) + hp = hist_get_oldest(); + else { + bi_errorf("%s: not in history", str); + hp = (char **) 0; + } + } else if (hp > histptr) { + if (approx) + hp = hist_get_newest(allow_cur); + else { + bi_errorf("%s: not in history", str); + hp = (char **) 0; + } + } else if (!allow_cur && hp == histptr) { + bi_errorf("%s: invalid range", str); + hp = (char **) 0; + } + } else { + int anchored = *str == '?' ? (++str, 0) : 1; + + /* the -1 is to avoid the current fc command */ + n = findhist(histptr - histlist - 1, 0, str, anchored); + if (n < 0) { + bi_errorf("%s: not in history", str); + hp = (char **) 0; + } else + hp = &histlist[n]; + } + return hp; +} + +/* Return a pointer to the newest command in the history */ +static char ** +hist_get_newest(allow_cur) + int allow_cur; +{ + if (histptr < histlist || (!allow_cur && histptr == histlist)) { + bi_errorf("no history (yet)"); + return (char **) 0; + } + if (allow_cur) + return histptr; + return histptr - 1; +} + +/* Return a pointer to the newest command in the history */ +static char ** +hist_get_oldest() +{ + if (histptr <= histlist) { + bi_errorf("no history (yet)"); + return (char **) 0; + } + return histlist; +} + +/******************************/ +/* Back up over last histsave */ +/******************************/ +static void +histbackup() +{ + static int last_line = -1; + + if (histptr >= histlist && last_line != hist_source->line) { + hist_source->line--; + afree((void*)*histptr, APERM); + histptr--; + last_line = hist_source->line; + } +} + +/* + * Return the current position. + */ +char ** +histpos() +{ + return current; +} + +int +histN() +{ + return curpos; +} + +int +histnum(n) + int n; +{ + int last = histptr - histlist; + + if (n < 0 || n >= last) { + current = histptr; + curpos = last; + return last; + } else { + current = &histlist[n]; + curpos = 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(start, fwd, str, anchored) + int start; + int fwd; + const char *str; + int anchored; +{ + char **hp; + int maxhist = histptr - histlist; + int incr = fwd ? 1 : -1; + int len = strlen(str); + + if (start < 0 || start >= maxhist) + start = maxhist; + + hp = &histlist[start]; + for (; hp >= histlist && hp <= histptr; hp += incr) + if ((anchored && strncmp(*hp, str, len) == 0) + || (!anchored && strstr(*hp, str))) + return hp - histlist; + + return -1; +} + +/* + * set history + * this means reallocating the dataspace + */ +void +sethistsize(n) + int n; +{ + if (n > 0 && n != histsize) { + int cursize = histptr - histlist; + + /* save most recent history */ + if (n < cursize) { + memmove(histlist, histptr - n, n * sizeof(char *)); + cursize = n; + } + + histlist = (char **)aresize(histlist, n*sizeof(char *), APERM); + + histsize = n; + histptr = histlist + cursize; + } +} + +/* + * set history file + * This can mean reloading/resetting/starting history file + * maintenance + */ +void +sethistfile(name) + 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 + */ +# ifdef EASY_HISTORY + if (hname) { + afree(hname, APERM); + hname = NULL; + } +# else + 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 = histlist - 1; + hist_source->line = 0; + } +# endif + + hist_init(hist_source); +} + +/* + * initialise the history vector + */ +void +init_histvec() +{ + if (histlist == NULL) { + histsize = HISTORYSIZE; + histlist = (char **)alloc(histsize*sizeof (char *), APERM); + histptr = histlist - 1; + } +} + +# ifdef EASY_HISTORY +/* + * save command in history + */ +void +histsave(lno, cmd, dowrite) + int lno; /* ignored (compatibility with COMPLEX_HISTORY) */ + const char *cmd; + int dowrite; /* ignored (compatibility with COMPLEX_HISTORY) */ +{ + char **hp = histptr; + char *cp; + + if (++hp >= histlist + histsize) { /* remove oldest command */ + afree((void*)histlist[0], APERM); + memmove(histlist, histlist + 1, + sizeof(histlist[0]) * (histsize - 1)); + hp = &histlist[histsize - 1]; + } + *hp = str_save(cmd, APERM); + /* trash trailing newline but allow imbedded newlines */ + cp = *hp + strlen(*hp); + if (cp > *hp && cp[-1] == '\n') + cp[-1] = '\0'; + histptr = hp; +} + +/* + * Append an entry to the last saved command. Used for multiline + * commands + */ +void +histappend(cmd, nl_separate) + const char *cmd; + int nl_separate; +{ + int hlen, clen; + char *p; + + hlen = strlen(*histptr); + clen = strlen(cmd); + if (clen > 0 && cmd[clen-1] == '\n') + clen--; + p = *histptr = (char *) aresize(*histptr, hlen + clen + 2, APERM); + p += hlen; + if (nl_separate) + *p++ = '\n'; + memcpy(p, cmd, clen); + p[clen] = '\0'; +} + +/* + * 92-04-25 <sjg@zen> + * A simple history file implementation. + * At present we only save the history when we exit. + * This can cause problems when there are multiple shells are + * running under the same user-id. The last shell to exit gets + * to save its history. + */ +void +hist_init(s) + Source *s; +{ + char *f; + FILE *fh; + + if (Flag(FTALKING) == 0) + return; + + hstarted = 1; + + hist_source = s; + + if ((f = str_val(global("HISTFILE"))) == NULL || *f == '\0') { +# if 1 /* Don't use history file unless the user asks for it */ + hname = NULL; + return; +# else + char *home = str_val(global("HOME")); + int len; + + if (home == NULL) + home = null; + f = HISTFILE; + hname = alloc(len = strlen(home) + strlen(f) + 2, APERM); + shf_snprintf(hname, len, "%s/%s", home, f); +# endif + } else + hname = str_save(f, APERM); + + if ((fh = fopen(hname, "r"))) { + int pos = 0, nread = 0; + int contin = 0; /* continuation of previous command */ + char *end; + char hline[LINE + 1]; + + while (1) { + if (pos >= nread) { + pos = 0; + nread = fread(hline, 1, LINE, fh); + if (nread <= 0) + break; + hline[nread] = '\0'; + } + end = strchr(hline + pos, 0); /* will always succeed */ + if (contin) + histappend(hline + pos, 0); + else { + hist_source->line++; + histsave(0, hline + pos, 0); + } + pos = end - hline + 1; + contin = end == &hline[nread]; + } + fclose(fh); + } +} + +/* + * save our history. + * We check that we do not have more than we are allowed. + * If the history file is read-only we do nothing. + * Handy for having all shells start with a useful history set. + */ + +void +hist_finish() +{ + static int once; + int fd; + FILE *fh; + int i; + char **hp; + + if (once++) + return; + if (hname == NULL || hname[0] == 0) + return; + + /* check how many we have */ + i = histptr - histlist; + if (i >= histsize) + hp = &histptr[-histsize]; + else + hp = histlist; + + if ((fd = open(hname, O_WRONLY | O_CREAT | O_TRUNC | O_EXLOCK, 0600)) != -1) { + /* Remove anything written before we got the lock */ + ftruncate(fd, 0); + if ((fh = fdopen(fd, "w")) != NULL) { + for (i = 0; hp + i <= histptr && hp[i]; i++) + fprintf(fh, "%s%c", hp[i], '\0'); + fclose(fh); + } + } +} + +# else /* EASY_HISTORY */ + +/* + * 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(lno, cmd, dowrite) + 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 >= histlist + histsize) { /* remove oldest command */ + afree((void*)*histlist, APERM); + for (hp = histlist; hp < histlist + 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(s) + Source *s; +{ + unsigned char *base; + int lines; + int fd; + + 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; + + histfd = savefd(fd, 0); + + (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_FLAGS, 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); +} + +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(base, bytes) + 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(oldbase, oldbytes) + unsigned char *oldbase; + int oldbytes; +{ + int fd; + char nfile[1024]; + 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 = creat(nfile, 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; + } + /* + * worry about who owns this file + */ + if (fstat(histfd, &statb) >= 0) + fchown(fd, statb.st_uid, statb.st_gid); + 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(base, bytes, no) + 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(s, base, bytes) + 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 >= histlist && 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(s, lno, line) + Source *s; + int lno; + unsigned char *line; +{ + char **hp; + + if (lno >= s->line-(histptr-histlist) && 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(lno, cmd) + 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_FLAGS, 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) flock(histfd, LOCK_UN); + (void) close(histfd); + histfd = 0; +} + +/* + * add magic to the history file + */ +static int +sprinkle(fd) + int fd; +{ + static unsigned char mag[] = { HMAGIC1, HMAGIC2 }; + + return(write(fd, mag, 2) != 2); +} + +# endif +#else /* HISTORY */ + +/* No history to be compiled in: dummy routines to avoid lots more ifdefs */ +void +init_histvec() +{ +} +void +hist_init(s) + Source *s; +{ +} +void +hist_finish() +{ +} +void +histsave(lno, cmd, dowrite) + int lno; + const char *cmd; + int dowrite; +{ + errorf("history not enabled"); +} +#endif /* HISTORY */ |