path: root/join.c

/* $OpenBSD: join.c,v 1.21 2009/10/27 23:59:39 deraadt Exp $    */

/*-
 * Copyright (c) 1991, 1993, 1994
 *  The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Steve Hayman of the Computer Science Department, Indiana University,
 * Michiro Hikida and David Goodenough.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* Required for Baserock build */

#include <getopt.h>

char *fgetln(FILE *stream, size_t *p_len) {
    static char *buffer = NULL;
    static size_t buffer_len = 0;
    size_t len;
    char c;

    len = 0;
    while(1) {
        if (feof(stream)) {
            *p_len = len;
            return len == 0? NULL : buffer;
        }

        c = fgetc(stream);
        if (c == '\n' || feof(stream)) {
            *p_len = len;
            return len == 0? NULL: buffer;
        }

        if (len >= buffer_len) {
            buffer_len = buffer_len==0? 80: buffer_len*2;
            buffer = realloc(buffer, buffer_len);
        }
        buffer[len] = c;
        len ++;
    }
}

/* End of Baserock fluff */

/*
 * There's a structure per input file which encapsulates the state of the
 * file.  We repeatedly read lines from each file until we've read in all
 * the consecutive lines from the file with a common join field.  Then we
 * compare the set of lines with an equivalent set from the other file.
 */
typedef struct {
    char *line;         /* line */
    u_long linealloc;       /* line allocated count */
    char **fields;          /* line field(s) */
    u_long fieldcnt;        /* line field(s) count */
    u_long fieldalloc;      /* line field(s) allocated count */
    u_long cfieldc;         /* current field count */
    long     fpos;          /* fpos of start of field */
} LINE;

typedef struct {
    FILE *fp;           /* file descriptor */
    u_long joinf;           /* join field (-1, -2, -j) */
    int unpair;         /* output unpairable lines (-a) */
    u_long number;          /* 1 for file 1, 2 for file 2 */
    LINE *set;          /* set of lines with same field */
    int pushbool;           /* if pushback is set */
    u_long pushback;        /* line on the stack */
    u_long setcnt;          /* set count */
    u_long setalloc;        /* set allocated count */
    u_long setusedc;        /* sets used  */
} INPUT;
INPUT input1 = { NULL, 0, 0, 1, NULL, 0, 0, 0, 0, 0 },
      input2 = { NULL, 0, 0, 2, NULL, 0, 0, 0, 0, 0 };

typedef struct {
    u_long  filenum;    /* file number */
    u_long  fieldno;    /* field number */
} OLIST;
OLIST *olist;           /* output field list */
u_long olistcnt;        /* output field list count */
u_long olistalloc;      /* output field allocated count */

int joinout = 1;        /* show lines with matched join fields (-v) */
int needsep;            /* need separator character */
int spans = 1;          /* span multiple delimiters (-t) */
char *empty;            /* empty field replacement string (-e) */
char *tabchar = " \t";      /* delimiter characters (-t) */

int  cmp(LINE *, u_long, LINE *, u_long);
void fieldarg(char *);
void joinlines(INPUT *, INPUT *);
void obsolete(char **);
void outfield(LINE *, u_long, int);
void outoneline(INPUT *, LINE *);
void outtwoline(INPUT *, LINE *, INPUT *, LINE *);
void slurp(INPUT *);
void slurpit(INPUT *);
void usage(void);

int
main(int argc, char *argv[])
{
    INPUT *F1, *F2;
    int aflag, ch, cval, vflag;
    char *end;

    F1 = &input1;
    F2 = &input2;

    aflag = vflag = 0;
    obsolete(argv);
    while ((ch = getopt(argc, argv, "\01a:e:j:1:2:o:t:v:")) != -1) {
        switch (ch) {
        case '\01':     /* See comment in obsolete(). */
            aflag = 1;
            F1->unpair = F2->unpair = 1;
            break;
        case '1':
            if ((F1->joinf = strtol(optarg, &end, 10)) < 1)
                errx(1, "-1 option field number less than 1");
            if (*end)
                errx(1, "illegal field number -- %s", optarg);
            --F1->joinf;
            break;
        case '2':
            if ((F2->joinf = strtol(optarg, &end, 10)) < 1)
                errx(1, "-2 option field number less than 1");
            if (*end)
                errx(1, "illegal field number -- %s", optarg);
            --F2->joinf;
            break;
        case 'a':
            aflag = 1;
            switch(strtol(optarg, &end, 10)) {
            case 1:
                F1->unpair = 1;
                break;
            case 2:
                F2->unpair = 1;
                break;
            default:
                errx(1, "-a option file number not 1 or 2");
                break;
            }
            if (*end)
                errx(1, "illegal file number -- %s", optarg);
            break;
        case 'e':
            empty = optarg;
            break;
        case 'j':
            if ((F1->joinf = F2->joinf = strtol(optarg, &end, 10)) < 1)
                errx(1, "-j option field number less than 1");
            if (*end)
                errx(1, "illegal field number -- %s", optarg);
            --F1->joinf;
            --F2->joinf;
            break;
        case 'o':
            fieldarg(optarg);
            break;
        case 't':
            spans = 0;
            if (strlen(tabchar = optarg) != 1)
                errx(1, "illegal tab character specification");
            break;
        case 'v':
            vflag = 1;
            joinout = 0;
            switch (strtol(optarg, &end, 10)) {
            case 1:
                F1->unpair = 1;
                break;
            case 2:
                F2->unpair = 1;
                break;
            default:
                errx(1, "-v option file number not 1 or 2");
                break;
            }
            if (*end)
                errx(1, "illegal file number -- %s", optarg);
            break;
        case '?':
        default:
            usage();
        }
    }
    argc -= optind;
    argv += optind;

    if (aflag && vflag)
        errx(1, "the -a and -v options are mutually exclusive");

    if (argc != 2)
        usage();

    /* Open the files; "-" means stdin. */
    if (!strcmp(*argv, "-"))
        F1->fp = stdin;
    else if ((F1->fp = fopen(*argv, "r")) == NULL)
        err(1, "%s", *argv);
    ++argv;
    if (!strcmp(*argv, "-"))
        F2->fp = stdin;
    else if ((F2->fp = fopen(*argv, "r")) == NULL)
        err(1, "%s", *argv);
    if (F1->fp == stdin && F2->fp == stdin)
        errx(1, "only one input file may be stdin");

    F1->setusedc = 0;
    F2->setusedc = 0;
    slurp(F1);
    slurp(F2);
    F1->set->cfieldc = 0;
    F2->set->cfieldc = 0;

    /*
     * We try to let the files have the same field value, advancing
     * whoever falls behind and always advancing the file(s) we output
     * from.
    */
    while (F1->setcnt && F2->setcnt) {
        cval = cmp(F1->set, F1->joinf, F2->set, F2->joinf);
        if (cval == 0) {
            /* Oh joy, oh rapture, oh beauty divine! */
            if (joinout)
                joinlines(F1, F2);
            slurp(F1);
            slurp(F2);
        }
        else {
            if (F1->unpair
            && (cval < 0 || F2->set->cfieldc == F2->setusedc -1)) {
                joinlines(F1, NULL);
                slurp(F1);
            }
            else if (cval < 0)  
                /* File 1 takes the lead... */
                slurp(F1);
            if (F2->unpair
            && (cval > 0 || F1->set->cfieldc == F1->setusedc -1)) {
                joinlines(F2, NULL);
                slurp(F2);
            }
            else if (cval > 0)
                /* File 2 takes the lead... */
                slurp(F2);
        }
    }

    /*
     * Now that one of the files is used up, optionally output any
     * remaining lines from the other file.
     */
    if (F1->unpair)
        while (F1->setcnt) {
            joinlines(F1, NULL);
            slurp(F1);
        }
    if (F2->unpair)
        while (F2->setcnt) {
            joinlines(F2, NULL);
            slurp(F2);
        }

    return 0;
}

/* wrapper around slurpit() to keep track of what field we are on */
void slurp(INPUT *F)
{
    long fpos;
    u_long cfieldc;

    if (F->set == NULL) {
        fpos = 0;
        cfieldc = 0;    
    }
    else {
        fpos = F->set->fpos;
        cfieldc = F->set->cfieldc;
    }
    slurpit(F);
    if (F->set == NULL)
        return;
    else if (fpos != F->set->fpos)
        F->set->cfieldc = cfieldc+1;
}   

void
slurpit(INPUT *F)
{
    LINE *lp, *lastlp, tmp;
    size_t len;
    u_long cnt;
    char *bp, *fieldp;
    long fpos;
    /*
     * Read all of the lines from an input file that have the same
     * join field.
     */

    F->setcnt = 0;
    for (lastlp = NULL; ; ++F->setcnt, lastlp = lp) {
        /*
         * If we're out of space to hold line structures, allocate
         * more.  Initialize the structure so that we know that this
         * is new space.
         */
        if (F->setcnt == F->setalloc) {
            LINE *p;
            u_long newsize = F->setalloc + 50;
            cnt = F->setalloc;
            if ((p = realloc(F->set,
                newsize * sizeof(LINE))) == NULL)
                err(1, NULL);
            F->set = p;
            F->setalloc = newsize;
            memset(F->set + cnt, 0, 50 * sizeof(LINE));
            /* re-set lastlp in case it moved */
            if (lastlp != NULL)
                lastlp = &F->set[F->setcnt - 1];
        }
        /*
         * Get any pushed back line, else get the next line.  Allocate
         * space as necessary.  If taking the line from the stack swap
         * the two structures so that we don't lose space allocated to
         * either structure.  This could be avoided by doing another
         * level of indirection, but it's probably okay as is.
         */
        lp = &F->set[F->setcnt];
        if (F->pushbool) {
            tmp = F->set[F->setcnt];
            F->set[F->setcnt] = F->set[F->pushback];
            F->set[F->pushback] = tmp;
            F->pushbool = 0;
            continue;
        }
        if ((bp = fgetln(F->fp, &len)) == NULL)
            return;
        /*
         * we depend on knowing on what field we are, one safe way is
         * the file position.
        */
        fpos = ftell(F->fp) - len;
        if (lp->linealloc <= len + 1) {
            char *p;
            u_long newsize = lp->linealloc +
                MAX(100, len + 1 - lp->linealloc);
            if ((p = realloc(lp->line, newsize)) == NULL)
                err(1, NULL);
            lp->line = p;
            lp->linealloc = newsize;
        }
        F->setusedc++;
        memmove(lp->line, bp, len);
        lp->fpos = fpos;
        /* Replace trailing newline, if it exists. */
        if (bp[len - 1] == '\n')
            lp->line[len - 1] = '\0';
        else
            lp->line[len] = '\0';
        bp = lp->line;

        /* Split the line into fields, allocate space as necessary. */
        lp->fieldcnt = 0;
        while ((fieldp = strsep(&bp, tabchar)) != NULL) {
            if (spans && *fieldp == '\0')
                continue;
            if (lp->fieldcnt == lp->fieldalloc) {
                char **p;
                u_long newsize = lp->fieldalloc + 50;
                if ((p = realloc(lp->fields,
                    newsize * sizeof(char *))) == NULL)
                    err(1, NULL);
                lp->fields = p;
                lp->fieldalloc = newsize;
            }
            lp->fields[lp->fieldcnt++] = fieldp;
        }

        /* See if the join field value has changed. */
        if (lastlp != NULL && cmp(lp, F->joinf, lastlp, F->joinf)) {
            F->pushbool = 1;
            F->pushback = F->setcnt;
            break;
        }
    }
}

int
cmp(LINE *lp1, u_long fieldno1, LINE *lp2, u_long fieldno2)
{
    if (lp1->fieldcnt <= fieldno1)
        return (-1);
    else if (lp2->fieldcnt <= fieldno2)
        return (1);
    return (strcmp(lp1->fields[fieldno1], lp2->fields[fieldno2]));
}

void
joinlines(INPUT *F1, INPUT *F2)
{
    u_long cnt1, cnt2;

    /*
     * Output the results of a join comparison.  The output may be from
     * either file 1 or file 2 (in which case the first argument is the
     * file from which to output) or from both.
     */
    if (F2 == NULL) {
        for (cnt1 = 0; cnt1 < F1->setcnt; ++cnt1)
            outoneline(F1, &F1->set[cnt1]);
        return;
    }
    for (cnt1 = 0; cnt1 < F1->setcnt; ++cnt1)
        for (cnt2 = 0; cnt2 < F2->setcnt; ++cnt2)
            outtwoline(F1, &F1->set[cnt1], F2, &F2->set[cnt2]);
}

void
outoneline(INPUT *F, LINE *lp)
{
    u_long cnt;

    /*
     * Output a single line from one of the files, according to the
     * join rules.  This happens when we are writing unmatched single
     * lines.  Output empty fields in the right places.
     */
    if (olist)
        for (cnt = 0; cnt < olistcnt; ++cnt) {
            if (olist[cnt].filenum == F->number)
                outfield(lp, olist[cnt].fieldno, 0);
            else if (olist[cnt].filenum == 0)
                outfield(lp, F->joinf, 0);
            else
                outfield(lp, 0, 1);
        }
    else {
        /*
         * Output the join field, then the remaining fields from F
         */
        outfield(lp, F->joinf, 0);
        for (cnt = 0; cnt < lp->fieldcnt; ++cnt)
            if (F->joinf != cnt)
                outfield(lp, cnt, 0);
    }

    putchar('\n');
    if (ferror(stdout))
        err(1, "stdout");
    needsep = 0;
}

void
outtwoline(INPUT *F1, LINE *lp1, INPUT *F2, LINE *lp2)
{
    u_long cnt;

    /* Output a pair of lines according to the join list (if any). */
    if (olist) {
        for (cnt = 0; cnt < olistcnt; ++cnt)
            if (olist[cnt].filenum == 0) {
                if (lp1->fieldcnt >= F1->joinf)
                    outfield(lp1, F1->joinf, 0);
                else
                    outfield(lp2, F2->joinf, 0);
            } else if (olist[cnt].filenum == 1)
                outfield(lp1, olist[cnt].fieldno, 0);
            else /* if (olist[cnt].filenum == 2) */
                outfield(lp2, olist[cnt].fieldno, 0);
    } else {
        /*
         * Output the join field, then the remaining fields from F1
         * and F2.
         */
        outfield(lp1, F1->joinf, 0);
        for (cnt = 0; cnt < lp1->fieldcnt; ++cnt)
            if (F1->joinf != cnt)
                outfield(lp1, cnt, 0);
        for (cnt = 0; cnt < lp2->fieldcnt; ++cnt)
            if (F2->joinf != cnt)
                outfield(lp2, cnt, 0);
    }
    putchar('\n');
    if (ferror(stdout))
        err(1, "stdout");
    needsep = 0;
}

void
outfield(LINE *lp, u_long fieldno, int out_empty)
{
    if (needsep++)
        putchar((int)*tabchar);
    if (!ferror(stdout)) {
        if (lp->fieldcnt <= fieldno || out_empty) {
            if (empty != NULL)
                fputs(empty, stdout);
        } else {
            if (*lp->fields[fieldno] == '\0')
                return;
            fputs(lp->fields[fieldno], stdout);
        }
    }
    if (ferror(stdout))
        err(1, "stdout");
}

/*
 * Convert an output list argument "2.1, 1.3, 2.4" into an array of output
 * fields.
 */
void
fieldarg(char *option)
{
    u_long fieldno, filenum;
    char *end, *token;

    while ((token = strsep(&option, ", \t")) != NULL) {
        if (*token == '\0')
            continue;
        if (token[0] == '0')
            filenum = fieldno = 0;
        else if ((token[0] == '1' || token[0] == '2') &&
            token[1] == '.') {
            filenum = token[0] - '0';
            fieldno = strtol(token + 2, &end, 10);
            if (*end)
                errx(1, "malformed -o option field");
            if (fieldno == 0)
                errx(1, "field numbers are 1 based");
            --fieldno;
        } else
            errx(1, "malformed -o option field");
        if (olistcnt == olistalloc) {
            OLIST *p;
            u_long newsize = olistalloc + 50;
            if ((p = realloc(olist,
                newsize * sizeof(OLIST))) == NULL)
                err(1, NULL);
            olist = p;
            olistalloc = newsize;
        }
        olist[olistcnt].filenum = filenum;
        olist[olistcnt].fieldno = fieldno;
        ++olistcnt;
    }
}

void
obsolete(char **argv)
{
    size_t len;
    char **p, *ap, *t;

    while ((ap = *++argv) != NULL) {
        /* Return if "--". */
        if (ap[0] == '-' && ap[1] == '-')
            return;
        /* skip if not an option */
        if (ap[0] != '-')
            continue;
        switch (ap[1]) {
        case 'a':
            /* 
             * The original join allowed "-a", which meant the
             * same as -a1 plus -a2.  POSIX 1003.2, Draft 11.2
             * only specifies this as "-a 1" and "a -2", so we
             * have to use another option flag, one that is
             * unlikely to ever be used or accidentally entered
             * on the command line.  (Well, we could reallocate
             * the argv array, but that hardly seems worthwhile.)
             */
            if (ap[2] == '\0' && (argv[1] == NULL ||
                (strcmp(argv[1], "1") != 0 &&
                strcmp(argv[1], "2") != 0))) {
                ap[1] = '\01';
                warnx("-a option used without an argument; "
                    "reverting to historical behavior");
            }
            break;
        case 'j':
            /*
             * The original join allowed "-j[12] arg" and "-j arg".
             * Convert the former to "-[12] arg".  Don't convert
             * the latter since getopt(3) can handle it.
             */
            switch(ap[2]) {
            case '1':
            case '2':
                if (ap[3] != '\0')
                    goto jbad;
                ap[1] = ap[2];
                ap[2] = '\0';
                break;
            case '\0':
                break;
            default:
jbad:               warnx("unknown option -- %s", ap + 1);
                usage();
            }
            break;
        case 'o':
            /*
             * The original join allowed "-o arg arg".
             * Convert to "-o arg -o arg".
             */
            if (ap[2] != '\0' || argv[1] == NULL)
                break;
            for (p = argv + 2; *p != NULL; ++p) {
                if (p[0][0] == '0' || ((p[0][0] != '1' &&
                    p[0][0] != '2') || p[0][1] != '.'))
                    break;
                len = strlen(*p);
                if (len - 2 != strspn(*p + 2, "0123456789"))
                    break;
                if ((t = malloc(len + 3)) == NULL)
                    err(1, NULL);
                t[0] = '-';
                t[1] = 'o';
                memmove(t + 2, *p, len + 1);
                *p = t;
            }
            argv = p - 1;
            break;
        }
    }
}

void
usage(void)
{
    int len;
    extern char *__progname;

    len = strlen(__progname) + sizeof("usage: ");
    (void)fprintf(stderr, "usage: %s [-1 field] [-2 field] "
        "[-a file_number | -v file_number] [-e string]\n"
        "%*s[-o list] [-t char] file1 file2\n",
        __progname, len, "");
    exit(1);
}