cmd/csh/sh.file.c

/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley Software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#ifdef FILEC
/*
 * Tenex style file name recognition, .. and more.
 * History:
 *  Author: Ken Greer, Sept. 1975, CMU.
 *  Finally got around to adding to the Cshell., Ken Greer, Dec. 1981.
 */

#include "sh.h"
#include <sys/types.h>
#include <dirent.h>
#include <pwd.h>
#include "sh.tconst.h"

#define TRUE    1
#define FALSE   0
#define ON  1
#define OFF 0

#define ESC '\033'

extern DIR *opendir_(tchar *);

static char *BELL = "\07";
static char *CTRLR = "^R\n";

typedef enum {LIST, RECOGNIZE} COMMAND;

static jmp_buf osetexit;        /* saved setexit() state */
static struct termios  tty_save;    /* saved terminal state */
static struct termios  tty_new;     /* new terminal state */

static int  is_prefix(tchar *, tchar *);
static int  is_suffix(tchar *, tchar *);
static int  ignored(tchar *);

/*
 * Put this here so the binary can be patched with adb to enable file
 * completion by default.  Filec controls completion, nobeep controls
 * ringing the terminal bell on incomplete expansions.
 */
bool filec = 0;

static void
setup_tty(int on)
{
    int omask;
#ifdef TRACE
    tprintf("TRACE- setup_tty()\n");
#endif

    omask = sigblock(sigmask(SIGINT));
    if (on) {
        /*
         * The shell makes sure that the tty is not in some weird state
         * and fixes it if it is.  But it should be noted that the
         * tenex routine will not work correctly in CBREAK or RAW mode
         * so this code below is, therefore, mandatory.
         *
         * Also, in order to recognize the ESC (filename-completion)
         * character, set EOL to ESC.  This way, ESC will terminate
         * the line, but still be in the input stream.
         * EOT (filename list) will also terminate the line,
         * but will not appear in the input stream.
         *
         * The getexit/setexit contortions ensure that the
         * tty state will be restored if the user types ^C.
         */
        (void) ioctl(SHIN, TCGETS,  (char *)&tty_save);
        getexit(osetexit);
        if (setjmp(reslab)) {
            (void) ioctl(SHIN, TCSETSW,  (char *)&tty_save);
            resexit(osetexit);
            reset();
        }
        tty_new = tty_save;
        tty_new.c_cc[VEOL] = ESC;
        tty_new.c_iflag |= IMAXBEL | BRKINT | IGNPAR;
        tty_new.c_lflag |= ICANON;
        tty_new.c_lflag |= ECHOCTL;
        tty_new.c_oflag &= ~OCRNL;
        (void) ioctl(SHIN, TCSETSW,  (char *)&tty_new);
    } else {
        /*
         * Reset terminal state to what user had when invoked
         */
        (void) ioctl(SHIN, TCSETSW,  (char *)&tty_save);
        resexit(osetexit);
    }
    (void) sigsetmask(omask);
}

static void
termchars(void)
{
    extern char *tgetstr();
    char bp[1024];
    static char area[256];
    static int been_here = 0;
    char *ap = area;
    char *s;
    char *term;

#ifdef TRACE
    tprintf("TRACE- termchars()\n");
#endif
    if (been_here)
        return;
    been_here = TRUE;

    if ((term = getenv("TERM")) == NULL)
        return;
    if (tgetent(bp, term) != 1)
        return;
    if (s = tgetstr("vb", &ap))     /* Visible Bell */
        BELL = s;
}

/*
 * Move back to beginning of current line
 */
static void
back_to_col_1(void)
{
    int omask;

#ifdef TRACE
    tprintf("TRACE- back_to_col_1()\n");
#endif
    omask = sigblock(sigmask(SIGINT));
    (void) write(SHOUT, "\r", 1);
    (void) sigsetmask(omask);
}

/*
 * Push string contents back into tty queue
 */
static void
pushback(tchar *string, int echoflag)
{
    tchar *p;
    struct termios tty;
    int omask, retry = 0;

#ifdef TRACE
    tprintf("TRACE- pushback()\n");
#endif
    omask = sigblock(sigmask(SIGINT));
    tty = tty_new;
    if (!echoflag)
        tty.c_lflag &= ~ECHO;

again:
    (void) ioctl(SHIN, TCSETSF, (char *)&tty);

    for (p = string; *p; p++) {
        char    mbc[MB_LEN_MAX];
        int i, j = wctomb(mbc, (wchar_t)*p);

        if (j < 0) {
            /* Error! But else what can we do? */
            continue;
        }
        for (i = 0; i < j; ++i) {
            if (ioctl(SHIN, TIOCSTI, mbc + i) != 0 &&
                errno == EAGAIN) {
                if (retry++ < 5)
                    goto again;
                /* probably no worth retrying any more */
            }
        }
    }

    if (tty.c_lflag != tty_new.c_lflag)
        (void) ioctl(SHIN, TCSETS,  (char *)&tty_new);
    (void) sigsetmask(omask);
}

/*
 * Concatenate src onto tail of des.
 * Des is a string whose maximum length is count.
 * Always null terminate.
 */
void
catn(tchar *des, tchar *src, int count)
{
#ifdef TRACE
    tprintf("TRACE- catn()\n");
#endif

    while (--count >= 0 && *des)
        des++;
    while (--count >= 0)
        if ((*des++ = *src++) == '\0')
            return;
    *des = '\0';
}

static int
max(a, b)
{

    return (a > b ? a : b);
}

/*
 * Like strncpy but always leave room for trailing \0
 * and always null terminate.
 */
void
copyn(tchar *des, tchar *src, int count)
{

#ifdef TRACE
    tprintf("TRACE- copyn()\n");
#endif
    while (--count >= 0)
        if ((*des++ = *src++) == '\0')
            return;
    *des = '\0';
}

/*
 * For qsort()
 */
static int
fcompare(tchar **file1, tchar **file2)
{

#ifdef TRACE
    tprintf("TRACE- fcompare()\n");
#endif
    return (strcoll_(*file1, *file2));
}

static char
filetype(tchar *dir, tchar *file, int nosym)
{
    tchar path[MAXPATHLEN + 1];
    struct stat statb;

#ifdef TRACE
    tprintf("TRACE- filetype()\n");
#endif
    if (dir) {
        catn(strcpy_(path, dir), file, MAXPATHLEN);
        if (nosym) {
            if (stat_(path, &statb) < 0)
                return (' ');
        } else {
            if (lstat_(path, &statb) < 0)
                return (' ');
        }
        if ((statb.st_mode & S_IFMT) == S_IFLNK)
            return ('@');
        if ((statb.st_mode & S_IFMT) == S_IFDIR)
            return ('/');
        if (((statb.st_mode & S_IFMT) == S_IFREG) &&
            (statb.st_mode & 011))
            return ('*');
    }
    return (' ');
}

/*
 * Print sorted down columns
 */
static void
print_by_column(tchar *dir, tchar *items[], int count, int looking_for_command)
{
    int i, rows, r, c, maxwidth = 0, columns;

#ifdef TRACE
    tprintf("TRACE- print_by_column()\n");
#endif
    for (i = 0; i < count; i++)
        maxwidth = max(maxwidth, tswidth(items[i]));

    /* for the file tag and space */
    maxwidth += looking_for_command ? 1 : 2;
    columns = max(78 / maxwidth, 1);
    rows = (count + (columns - 1)) / columns;

    for (r = 0; r < rows; r++) {
        for (c = 0; c < columns; c++) {
            i = c * rows + r;
            if (i < count) {
                int w;

                /*
                 * Print filename followed by
                 * '@' or '/' or '*' or ' '
                 */
                printf("%t", items[i]);
                w = tswidth(items[i]);
                if (!looking_for_command) {
                    printf("%c",
                        (tchar) filetype(dir, items[i], 0));
                    w++;
                }
                if (c < columns - 1)    /* last column? */
                    for (; w < maxwidth; w++)
                        printf(" ");
            }
        }
        printf("\n");
    }
}

/*
 * Expand file name with possible tilde usage
 *  ~person/mumble
 * expands to
 *  home_directory_of_person/mumble
 */
tchar *
tilde(tchar *new, tchar *old)
{
    tchar *o, *p;
    struct passwd *pw;
    static tchar person[40];
    char person_[40];       /* work */
    tchar *pw_dir;          /* work */

#ifdef TRACE
    tprintf("TRACE- tilde()\n");
#endif
    if (old[0] != '~')
        return (strcpy_(new, old));

    for (p = person, o = &old[1]; *o && *o != '/'; *p++ = *o++)
        ;
    *p = '\0';
    if (person[0] == '\0')
        (void) strcpy_(new, value(S_home /* "home" */));
    else {
        pw = getpwnam(tstostr(person_, person));
        if (pw == NULL)
            return (NULL);
        pw_dir = strtots((tchar *)NULL, pw->pw_dir);    /* allocate */
        (void) strcpy_(new, pw_dir);
        xfree(pw_dir);                  /* free it */
    }
    (void) strcat_(new, o);
    return (new);
}

/*
 * Cause pending line to be printed
 */
static void
sim_retype(void)
{
#ifdef notdef
    struct termios tty_pending;

#ifdef TRACE
    tprintf("TRACE- sim_retypr()\n");
#endif
    tty_pending = tty_new;
    tty_pending.c_lflag |= PENDIN;

    (void) ioctl(SHIN, TCSETS,  (char *)&tty_pending);
#else
#ifdef TRACE
    tprintf("TRACE- sim_retype()\n");
#endif
    (void) write(SHOUT, CTRLR, strlen(CTRLR));
    printprompt();
#endif
}

static int
beep_outc(int c)
{
    char    buf[1];

    buf[0] = c;

    (void) write(SHOUT, buf, 1);

    return 0;
}

static void
beep(void)
{

#ifdef TRACE
    tprintf("TRACE- beep()\n");
#endif
    if (adrof(S_nobeep /* "nobeep" */) == 0)
        (void) tputs(BELL, 0, beep_outc);
}

/*
 * Erase that silly ^[ and print the recognized part of the string.
 */
static void
print_recognized_stuff(tchar *recognized_part)
{
    int unit =  didfds ? 1 : SHOUT;

#ifdef TRACE
    tprintf("TRACE- print_recognized_stuff()\n");
#endif

    /*
     * An optimized erasing of that silly ^[
     *
     * One would think that line speeds have become fast enough that this
     * isn't necessary, but it turns out that the visual difference is
     * quite noticeable.
     */
    flush();
    switch (tswidth(recognized_part)) {
    case 0:
        /* erase two characters: ^[ */
        write(unit, "\b\b  \b\b", sizeof "\b\b  \b\b" - 1);
        break;

    case 1:
        /* overstrike the ^, erase the [ */
        write(unit, "\b\b", 2);
        printf("%t", recognized_part);
        write(unit, "  \b\b", 4);
        break;

    default:
        /* overstrike both characters ^[ */
        write(unit, "\b\b", 2);
        printf("%t", recognized_part);
        break;
    }
    flush();
}

/*
 * Parse full path in file into 2 parts: directory and file names
 * Should leave final slash (/) at end of dir.
 */
static void
extract_dir_and_name(tchar *path, tchar *dir, tchar *name)
{
    tchar  *p;

#ifdef TRACE
    tprintf("TRACE- extract_dir_and_name()\n");
#endif
    p = rindex_(path, '/');
    if (p == NOSTR) {
        copyn(name, path, MAXNAMLEN);
        dir[0] = '\0';
    } else {
        copyn(name, ++p, MAXNAMLEN);
        copyn(dir, path, p - path);
    }
}

tchar *
getentry(DIR *dir_fd, int looking_for_lognames)
{
    struct passwd *pw;
    struct dirent *dirp;
    /*
     * For char * -> tchar * Conversion
     */
    static tchar strbuf[MAXNAMLEN+1];

#ifdef TRACE
    tprintf("TRACE- getentry()\n");
#endif
    if (looking_for_lognames) {
        if ((pw = getpwent()) == NULL)
            return (NULL);
        return (strtots(strbuf, pw->pw_name));
    }
    if (dirp = readdir(dir_fd))
        return (strtots(strbuf, dirp->d_name));
    return (NULL);
}

static void
free_items(tchar **items)
{
    int i;

#ifdef TRACE
    tprintf("TRACE- free_items()\n");
#endif
    for (i = 0; items[i]; i++)
        xfree(items[i]);
    xfree((char *)items);
}

#define FREE_ITEMS(items) { \
    int omask;\
\
    omask = sigblock(sigmask(SIGINT));\
    free_items(items);\
    items = NULL;\
    (void) sigsetmask(omask);\
}

/*
 * Perform a RECOGNIZE or LIST command on string "word".
 */
static int
search2(tchar *word, COMMAND command, int max_word_length)
{
    static tchar **items = NULL;
    DIR *dir_fd;
    int numitems = 0, ignoring = TRUE, nignored = 0;
    int name_length, looking_for_lognames;
    tchar tilded_dir[MAXPATHLEN + 1], dir[MAXPATHLEN + 1];
    tchar name[MAXNAMLEN + 1], extended_name[MAXNAMLEN+1];
    tchar *entry;
#define MAXITEMS 1024
#ifdef TRACE
    tprintf("TRACE- search2()\n");
#endif

    if (items != NULL)
        FREE_ITEMS(items);

    looking_for_lognames = (*word == '~') && (index_(word, '/') == NULL);
    if (looking_for_lognames) {
        (void) setpwent();
        copyn(name, &word[1], MAXNAMLEN);   /* name sans ~ */
    } else {
        extract_dir_and_name(word, dir, name);
        if (tilde(tilded_dir, dir) == 0)
            return (0);
        dir_fd = opendir_(*tilded_dir ? tilded_dir : S_DOT /* "." */);
        if (dir_fd == NULL)
            return (0);
    }

again:  /* search for matches */
    name_length = strlen_(name);
    for (numitems = 0; entry = getentry(dir_fd, looking_for_lognames); ) {
        if (!is_prefix(name, entry))
            continue;
        /* Don't match . files on null prefix match */
        if (name_length == 0 && entry[0] == '.' &&
            !looking_for_lognames)
            continue;
        if (command == LIST) {
            if (numitems >= MAXITEMS) {
                printf("\nYikes!! Too many %s!!\n",
                    looking_for_lognames ?
                    "names in password file":"files");
                break;
            }
            if (items == NULL)
                items =  (tchar **)xcalloc(sizeof (items[1]),
                    MAXITEMS+1);
            items[numitems] = (tchar *)xalloc((unsigned)(strlen_(entry) + 1) * sizeof (tchar));
            copyn(items[numitems], entry, MAXNAMLEN);
            numitems++;
        } else {            /* RECOGNIZE command */
            if (ignoring && ignored(entry))
                nignored++;
            else if (recognize(extended_name,
                entry, name_length, ++numitems))
                break;
        }
    }
    if (ignoring && numitems == 0 && nignored > 0) {
        ignoring = FALSE;
        nignored = 0;
        if (looking_for_lognames)
            (void) setpwent();
        else
            rewinddir(dir_fd);
        goto again;
    }

    if (looking_for_lognames)
        (void) endpwent();
    else {
        unsetfd(dir_fd->dd_fd);
        closedir_(dir_fd);
    }
    if (command == RECOGNIZE && numitems > 0) {
        if (looking_for_lognames)
            copyn(word, S_TIL /* "~" */, 1);
        else
            /* put back dir part */
            copyn(word, dir, max_word_length);
        /* add extended name */
        catn(word, extended_name, max_word_length);
        return (numitems);
    }
    if (command == LIST) {
        qsort((char *)items, numitems, sizeof (items[1]),
            (int (*)(const void *, const void *))fcompare);
        /*
         * Never looking for commands in this version, so final
         * argument forced to 0.  If command name completion is
         * reinstated, this must change.
         */
        print_by_column(looking_for_lognames ? NULL : tilded_dir,
            items, numitems, 0);
        if (items != NULL)
            FREE_ITEMS(items);
    }
    return (0);
}

/*
 * Object: extend what user typed up to an ambiguity.
 * Algorithm:
 * On first match, copy full entry (assume it'll be the only match)
 * On subsequent matches, shorten extended_name to the first
 * character mismatch between extended_name and entry.
 * If we shorten it back to the prefix length, stop searching.
 */
int
recognize(tchar *extended_name, tchar *entry, int name_length, int numitems)
{

#ifdef TRACE
    tprintf("TRACE- recognize()\n");
#endif
    if (numitems == 1)              /* 1st match */
        copyn(extended_name, entry, MAXNAMLEN);
    else {                  /* 2nd and subsequent matches */
        tchar *x, *ent;
        int len = 0;

        x = extended_name;
        for (ent = entry; *x && *x == *ent++; x++, len++)
            ;
        *x = '\0';          /* Shorten at 1st char diff */
        if (len == name_length)     /* Ambiguous to prefix? */
            return (-1);        /* So stop now and save time */
    }
    return (0);
}

/*
 * Return true if check items initial chars in template
 * This differs from PWB imatch in that if check is null
 * it items anything
 */
static int
is_prefix(tchar *check, tchar *template)
{
#ifdef TRACE
    tprintf("TRACE- is_prefix()\n");
#endif

    do
        if (*check == 0)
            return (TRUE);
    while (*check++ == *template++);
    return (FALSE);
}

/*
 *  Return true if the chars in template appear at the
 *  end of check, i.e., are its suffix.
 */
static int
is_suffix(tchar *check, tchar *template)
{
    tchar *c, *t;

#ifdef TRACE
    tprintf("TRACE- is_suffix()\n");
#endif
    for (c = check; *c++; )
        ;
    for (t = template; *t++; )
        ;
    for (;;) {
        if (t == template)
            return (TRUE);
        if (c == check || *--t != *--c)
            return (FALSE);
    }
}

int
tenex(tchar *inputline, int inputline_size)
{
    int numitems, num_read, should_retype;
    int i;

#ifdef TRACE
    tprintf("TRACE- tenex()\n");
#endif
    setup_tty(ON);
    termchars();
    num_read = 0;
    should_retype = FALSE;
    while ((i = read_(SHIN, inputline+num_read, inputline_size-num_read))
        > 0) {
        static tchar *delims = S_DELIM /* " '\"\t;&<>()|`" */;
        tchar *str_end, *word_start, last_char;
        int space_left;
        struct termios tty;
        COMMAND command;

        num_read += i;
        inputline[num_read] = '\0';
        last_char = inputline[num_read - 1] & TRIM;

        /*
         * read_() can return more than requested size if there
         * is multibyte character at the end.
         */
        if ((num_read >= inputline_size) || (last_char == '\n'))
            break;

        str_end = &inputline[num_read];
        if (last_char == ESC) {
            command = RECOGNIZE;
            *--str_end = '\0';  /* wipe out trailing ESC */
        } else
            command = LIST;

        tty = tty_new;
        tty.c_lflag &= ~ECHO;
        (void) ioctl(SHIN, TCSETSF, (char *)&tty);

        if (command == LIST)
            printf("\n");
        /*
         * Find LAST occurence of a delimiter in the inputline.
         * The word start is one character past it.
         */
        for (word_start = str_end; word_start > inputline;
            --word_start) {
            if (index_(delims, word_start[-1]) ||
                isauxsp(word_start[-1]))
                break;
        }
        space_left = inputline_size - (word_start - inputline) - 1;
        numitems = search2(word_start, command, space_left);

        /*
         * Tabs in the input line cause trouble after a pushback.
         * tty driver won't backspace over them because column
         * positions are now incorrect. This is solved by retyping
         * over current line.
         */
        if (index_(inputline, '\t')) {  /* tab tchar in input line? */
            back_to_col_1();
            should_retype = TRUE;
        }
        if (command == LIST)        /* Always retype after a LIST */
            should_retype = TRUE;
        if (should_retype)
            printprompt();
        pushback(inputline, should_retype);
        num_read = 0;           /* chars will be reread */
        should_retype = FALSE;

        /*
         * Avoid a race condition by echoing what we're recognized
         * _after_ pushing back the command line.  This way, if the
         * user waits until seeing this output before typing more
         * stuff, the resulting keystrokes won't race with the STIed
         * input we've pushed back.  (Of course, if the user types
         * ahead, the race still exists and it's quite possible that
         * the pushed back input line will interleave with the
         * keystrokes in unexpected ways.)
         */
        if (command == RECOGNIZE) {
            /* print from str_end on */
            print_recognized_stuff(str_end);
            if (numitems != 1)  /* Beep = No match/ambiguous */
                beep();
        }
    }
    setup_tty(OFF);
    return (num_read);
}

static int
ignored(tchar *entry)
{
    struct varent *vp;
    tchar **cp;

#ifdef TRACE
    tprintf("TRACE- ignored()\n");
#endif
    if ((vp = adrof(S_fignore /* "fignore" */)) == NULL ||
        (cp = vp->vec) == NULL)
        return (FALSE);
    for (; *cp != NULL; cp++)
        if (is_suffix(entry, *cp))
            return (TRUE);
    return (FALSE);
}
#endif /* FILEC */