cmd/re/sed2.c

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*          Copyright (c) 1995-2012 AT&T Intellectual Property          *
*                      and is licensed under the                       *
*                 Eclipse Public License, Version 1.0                  *
*                    by AT&T Intellectual Property                     *
*                                                                      *
*                A copy of the License is available at                 *
*          http://www.eclipse.org/org/documents/epl-v10.html           *
*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                                                                      *
***********************************************************************/
#pragma prototyped

#include "sed.h"

#include <ctype.h>

#define ustrchr(p, c) (unsigned char*)strchr((char*)(p), c)

int selected(unsigned char*, Text*);

#define Re Ie
#define Ce Ie
#define Se Ie
#define re ae

#define IBUG "interpreter bug %d"
char *stdouterr = "writing standard output";

Text hold;

void
cputchar(int c)
{
    if(sfputc(sfstdout, c) == EOF)
        error(ERROR_SYSTEM|3, stdouterr);
}

void
writeline(Text *data)
{
    word n = data->w - data->s;
    if(sfwrite(sfstdout, data->s, n) != n)
        error(ERROR_SYSTEM|3, stdouterr);
    cputchar('\n');
}

/* return 1 if action is to be taken on current line,
         -1 if (numeric) address has been passed,
      0 otherwise*/
int
sel1(word addr, Text *data)
{
    if(addr & REGADR)
        return reexec(readdr(addr), (char*)data->s, data->w - data->s, 0, 0, 0) == 0;
    if(addr == recno)
        return 1;
    if(addr == DOLLAR)
        return ateof();
    if(addr < recno)
        return -1;
    return 0;
}

/* return 2 on non-final line of a selected range,
          1 on any other selected line,
      0 on non-selected lines
   (the 1-2 distinction matters only for 'c' commands) */

int
selected(unsigned char *pc, Text *data)
{
    int active;
    word *ipc = (word*)pc;  /* points to address words */
    word *q = instr(pc);    /* points to instruction word */
    int neg = !!(*q & NEG);
    switch(q - ipc) {
    case 0:         /* 0 address */
        return !neg;
    case 1:         /* 1 address */
        return neg ^ (sel1(ipc[0], data)==1);
    case 2:
        error(ERROR_PANIC|4, IBUG,1);
    case 3:         /* 2 address */
        q--;        /* points to activity indicator */
        active = !(*q & INACT);
        if((*q&AMASK) < recno) {
            switch(sel1(ipc[active], data)) {
            case 0:
                if((active&ateof()) == 0)
                    break;
            case 1:
                *q = recno;
                if(active)
                    *q |= INACT;
                return (neg^1) << (!active&!ateof());
            case -1:
                if(active) {
                    *q = recno | INACT;
                    return neg;
                }
            }
        }
        return (neg^active) << 1;
    default:
        error(ERROR_PANIC|4, IBUG,2);
        return 0;   /* dummy */
    }
}

void
vacate(Text *t)
{
    assure(t, 1);
    t->w = t->s;
    *t->w = 0;
}

void
tcopy(Text *from, Text *to)
{
    word n = from->w - from->s;
    assure(to, n+1);
    memmove(to->w, from->s, n);
    to->w += n;
    *to->w = 0;
}


/* EASY COMMANDS */

unsigned char *
vv(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    pc = pc;
    data = data;
    error(ERROR_PANIC|4, IBUG,3);
    return 0;   /* dummy */
}

unsigned char *
be(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    data = data;
    return script->s + instr(pc)[1];
}

unsigned char *
de(Text *script, unsigned char *pc, Text *data)
{
    NoP(script);
    pc = pc;
    vacate(data);
    return 0;
}

unsigned char *
De(Text *script, unsigned char *pc, Text *data)
{
    word n;
    unsigned char *end = (unsigned char*)ustrchr(data->s, '\n');
    if(end == 0)
        return de(script, pc, data);
    end++;
    n = data->w - end;
    memmove(data->s, end, n+1);
    data->w = data->s + n;
    return script->s;
}

unsigned char *
Ee(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    data = data;
    if(sfprintf(sfstdout, "%d\n", recno) <= 0)
        error(ERROR_SYSTEM|3, stdouterr);
    return nexti(pc);
}

unsigned char *
Ge(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    if(hold.s == 0)
        vacate(&hold);
    *data->w++ = '\n';
    tcopy(&hold, data);
    return nexti(pc);
}

unsigned char *
ge(Text *script, unsigned char *pc, Text *data)
{
    vacate(data);
    script = script;
    if(hold.s == 0)
        vacate(&hold);
    if(data->w > data->s)
        *data->w++ = '\n';
    tcopy(&hold, data);
    return nexti(pc);
}

unsigned char *
He(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    assure(&hold, 1);
    *hold.w++ = '\n';
    tcopy(data, &hold);
    return nexti(pc);
}

unsigned char *
he(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    vacate(&hold);
    tcopy(data, &hold);
    return nexti(pc);
}

unsigned char *
Ie(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    data = data;
    return nexti(pc);
}

unsigned char *
ie(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    data = data;
    if(sfprintf(sfstdout, "%s", (char*)(instr(pc)+1)) <= 0)
        error(ERROR_SYSTEM|3, stdouterr);
    return nexti(pc);
}

unsigned char *
Le(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    data = data;
    return (unsigned char*)(instr(pc)+1);
}

unsigned char *
Ne(Text *script, unsigned char *pc, Text *data)
{
    assure(data, 1);
    *data->w++ = '\n';
    if(readline(data))
        return nexti(pc);
    *--data->w = 0;
    return de(script, pc, data);
}

unsigned char *
ne(Text *script, unsigned char *pc, Text *data)
{
    NoP(script);
    if(!nflag)
        writeline(data);
    vacate(data);
    if(readline(data))
        return nexti(pc);
    return 0;
}

unsigned char *
Pe(Text *script, unsigned char *pc, Text *data)
{
    word n;
    unsigned char *end = ustrchr(data->s, '\n');
    if(end == 0)
        n = data->w - data->s;
    else
        n = end - data->s;
    if(sfwrite(sfstdout, data->s, n) != n)
        error(ERROR_SYSTEM|3, stdouterr);
    cputchar('\n');
    script = script;
    return nexti(pc);
}

unsigned char *
pe(Text *script, unsigned char *pc, Text *data)
{
    writeline(data);
    script = script;
    return nexti(pc);
}

unsigned char *
qe(Text *script, unsigned char *pc, Text *data)
{
    pc = pc;
    data = data;
    qflag++;
    return script->w;
}

unsigned char *
te(Text *script, unsigned char *pc, Text *data)
{
    int tflag = sflag;
    sflag = 0;
    if(tflag)
        return be(script, pc, data);
    else
        return nexti(pc);
}

unsigned char *
ww(Text *script, unsigned char *pc, Text *data, word offset)
{
    word *q = (word*)(files.s + offset);
    Sfio_t *f = *(Sfio_t**)q;
    word n = data->w - data->s;
    assure(data, 1);
    *data->w = '\n';
    if(sfwrite(f, data->s, n+1) != n+1 ||
       sfsync(f) == EOF)    /* in case of subsequent r */
        error(ERROR_SYSTEM|3, "%s: cannot write", (char*)(q+1));
    *data->w = 0;
    script = script;
    return nexti(pc);
}

unsigned char *
we(Text *script, unsigned char *pc, Text *data)
{
    return ww(script, pc, data, instr(pc)[1]);
}

unsigned char *
xe(Text *script, unsigned char *pc, Text *data)
{
    unsigned char *t;
    script = script;
    if(hold.s == 0)
        vacate(&hold);
    exch(data->s, hold.s, t);
    exch(data->e, hold.e, t);
    exch(data->w, hold.w, t);
    return nexti(pc);
}

unsigned char *
ye(Text *script, unsigned char *pc, Text *data)
{
    unsigned char *s = (unsigned char*)data->s;
    unsigned char *w = (unsigned char*)data->w;
    unsigned char **m = (unsigned char**)(instr(pc)+1);
    unsigned char *b;
    unsigned int c, x;
    int i, n;
    Sfio_t *f;
    if(x = (unsigned int)(*m++ - (unsigned char*)0)) {
        if(!(f = sfstropen()))
            error(ERROR_SYSTEM|3, "out of space");
        while(s<w) {
            b = s;
            c = mbchar(s);
            if(c < x && m[c]) {
                n = m[c][0];
                i = 0;
                while(++i<=n)
                    sfputc(f, m[c][i]);
            }
            else
                while(b<s)
                    sfputc(f, *b++);
        }
        x = (unsigned int)sfstrtell(f);
        assure(data, x);
        memcpy(data->s, sfstrbase(f), x);
        data->w = data->s + x;
    }
    else
        for(b = (unsigned char*)m; s<w; s++)
            *s = b[*s];
    script = script;
    return nexti(pc);
}

/* MISCELLANY */

unsigned char *
se(Text *script, unsigned char *pc, Text *data)
{
    word *q = instr(pc);
    int flags = readdr(q[1])->re_sub->re_flags;

    sflag = substitute(readdr(q[1]), data);
    if(!sflag)
        return nexti(pc);
    if(flags & REG_SUB_PRINT)
        pe(script, pc, data);
    if(flags & REG_SUB_WRITE)
        return ww(script, pc, data, ((word*)nexti(pc))[-1]);
    return nexti(pc);
}

struct { char p, q; } digram[] = {
    '\\',   '\\',
    '\a',   'a',
    '\b',   'b',
    '\f',   'f',
    '\n',   'n',
    '\r',   'r',
    '\t',   't',
    '\v',   'v',
};

#define LEMAX   72
#define CHMAX   4

unsigned char *
le(Text *script, unsigned char *pc, Text *data)
{
    word n;
    int j;
    unsigned char *s;
    unsigned char *b;
    unsigned char *o;
    unsigned char *e;
    unsigned char buf[LEMAX+CHMAX+1];
    script = script;
    b = buf;
    for(s=data->s; s<data->w; s++) {
        o = b;
        for(j=0; j<sizeof(digram)/sizeof(*digram); j++)
            if(*s == digram[j].p) {
                *b++ = '\\';
                *b++ = digram[j].q;
                goto hit;
            }
        if(!isprint(*s))
            b += sfsprintf((char*)b, CHMAX+1, "\\%3.3o", *s);
        else
            *b++ = *s;
    hit:
        if((b - buf) >= LEMAX) {
            n = o - buf;
            if(sfwrite(sfstdout, buf, n) != n)
                error(ERROR_SYSTEM|3, stdouterr);
            cputchar('\\');
            cputchar('\n');
            e = b;
            b = buf;
            while(o < e)
                *b++ = *o++;
        }
    }
    *b++ = '$';
    *b++ = '\n';
    n = b - buf;
    if(sfwrite(sfstdout, buf, n) != n)
        error(ERROR_SYSTEM|3, stdouterr);
    return nexti(pc);
}

/* END-OF-CYCLE STUFF */

Text todo;

unsigned char *
ae(Text *script, unsigned char *pc, Text *data)
{
    script = script;
    data = data;
    assure(&todo, sizeof(unsigned char*));
    *(unsigned char**)todo.w = pc;
    todo.w += sizeof(unsigned char*);
    return nexti(pc);
}

unsigned char *
ce(Text *script, unsigned char *pc, Text *data)
{
    if(sfprintf(sfstdout, "%s", (char*)(instr(pc)+1)) <= 0)
        error(ERROR_SYSTEM|3, stdouterr);
    return de(script, pc, data);
}

void
coda(void)
{
    word *q;
    unsigned char *p;
    Sfio_t *f;
    if(todo.s == 0)
        return;
    for(p=todo.s; p<todo.w; p+=sizeof(word)) {
        q = instr(*(unsigned char**)p);
        switch(code(*q)) {
        case 'a':
            if(sfprintf(sfstdout, "%s", (char*)(q+1)) <= 0)
                error(ERROR_SYSTEM|3, stdouterr);
            continue;
        case 'r':
            f = sfopen(NiL, (char*)(files.s+q[1]+sizeof(word)), "r");
            if(f == 0)
                continue;
            if (sfmove(f, sfstdout, SF_UNBOUND, -1) < 0 || sferror(sfstdout) || !sfeof(f))
                error(ERROR_SYSTEM|3, stdouterr);
            sfclose(f);
            continue;
        default:
            error(ERROR_PANIC|4, IBUG,5);
        }
    }
    vacate(&todo);
}

/* execution functions return pointer to next instruction */

typedef unsigned char* (*exef)(Text*, unsigned char *, Text*);

static const exef excom[128] = {
    vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,Ie,vv,vv,vv,vv,vv,
    vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,
    vv,vv,vv,Ie,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv, /* # */
    vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,Ce,Se,vv,Ee,vv,vv, /* :;= */
    vv,vv,vv,vv,De,vv,vv,Ge,He,vv,vv,vv,vv,vv,Ne,vv, /* DGHN */
    Pe,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv,vv, /* P */
    vv,ae,be,ce,de,vv,vv,ge,he,ie,vv,vv,le,vv,ne,vv, /* a-n */
    pe,qe,re,se,te,vv,vv,we,xe,ye,vv,Le,vv,Re,vv,vv  /* p-y{} */
};

void
execute(Text *script, Text *data)
{
    unsigned char *pc;
    int sel;
    for(pc = script->s; pc < script->w; ) {
        sel = selected(pc, data);
        if(sel) {
            int cmd = code(*instr(pc));
            if(sel==2 && cmd=='c')
                cmd = 'd';
            pc = (*excom[ccmapchr(map,cmd)])(script, pc, data);
            if(pc == 0)
                return;
        } else
            pc = nexti(pc);
    }
    if(!nflag)
        writeline(data);
}