/*
* field.c - routines for dealing with fields and record parsing
*/
/*
* Copyright (C) 1986, 1988, 1989, 1991-1997 the Free Software Foundation, Inc.
*
* This file is part of GAWK, the GNU implementation of the
* AWK Programming Language.
*
* GAWK is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GAWK is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include "awk.h"
#include <assert.h>
typedef void (* Setfunc) P((long, char *, long, NODE *));
static long (*parse_field) P((long, char **, int, NODE *,
Regexp *, Setfunc, NODE *));
static void rebuild_record P((void));
static long re_parse_field P((long, char **, int, NODE *,
Regexp *, Setfunc, NODE *));
static long def_parse_field P((long, char **, int, NODE *,
Regexp *, Setfunc, NODE *));
static long posix_def_parse_field P((long, char **, int, NODE *,
Regexp *, Setfunc, NODE *));
static long null_parse_field P((long, char **, int, NODE *,
Regexp *, Setfunc, NODE *));
static long sc_parse_field P((long, char **, int, NODE *,
Regexp *, Setfunc, NODE *));
static long fw_parse_field P((long, char **, int, NODE *,
Regexp *, Setfunc, NODE *));
static void set_element P((long num, char * str, long len, NODE *arr));
static void grow_fields_arr P((long num));
static void set_field P((long num, char *str, long len, NODE *dummy));
static char *parse_extent; /* marks where to restart parse of record */
static long parse_high_water = 0; /* field number that we have parsed so far */
static long nf_high_water = 0; /* size of fields_arr */
static int resave_fs;
static NODE *save_FS; /* save current value of FS when line is read,
* to be used in deferred parsing
*/
static int *FIELDWIDTHS = NULL;
NODE **fields_arr; /* array of pointers to the field nodes */
int field0_valid; /* $(>0) has not been changed yet */
int default_FS; /* TRUE when FS == " " */
Regexp *FS_regexp = NULL;
static NODE *Null_field = NULL;
/* init_fields --- set up the fields array to start with */
void
init_fields()
{
NODE *n;
emalloc(fields_arr, NODE **, sizeof(NODE *), "init_fields");
getnode(n);
*n = *Nnull_string;
n->flags |= (SCALAR|FIELD);
n->flags &= ~PERM;
fields_arr[0] = n;
parse_extent = fields_arr[0]->stptr;
save_FS = dupnode(FS_node->var_value);
getnode(Null_field);
*Null_field = *Nnull_string;
Null_field->flags |= (SCALAR|FIELD);
Null_field->flags &= ~(NUM|NUMBER|MAYBE_NUM|PERM);
field0_valid = TRUE;
}
/* grow_fields --- acquire new fields as needed */
static void
grow_fields_arr(num)
long num;
{
register int t;
register NODE *n;
erealloc(fields_arr, NODE **, (num + 1) * sizeof(NODE *), "grow_fields_arr");
for (t = nf_high_water + 1; t <= num; t++) {
getnode(n);
*n = *Null_field;
fields_arr[t] = n;
}
nf_high_water = num;
}
/* set_field --- set the value of a particular field */
/*ARGSUSED*/
static void
set_field(num, str, len, dummy)
long num;
char *str;
long len;
NODE *dummy; /* not used -- just to make interface same as set_element */
{
register NODE *n;
if (num > nf_high_water)
grow_fields_arr(num);
n = fields_arr[num];
n->stptr = str;
n->stlen = len;
n->flags = (STR|STRING|MAYBE_NUM|SCALAR|FIELD);
}
/* rebuild_record --- Someone assigned a value to $(something).
Fix up $0 to be right */
static void
rebuild_record()
{
/*
* use explicit unsigned longs for lengths, in case
* a size_t isn't big enough.
*/
register unsigned long tlen;
register unsigned long ofslen;
register NODE *tmp;
NODE *ofs;
char *ops;
register char *cops;
long i;
char *f0start, *f0end;
assert(NF != -1);
tlen = 0;
ofs = force_string(OFS_node->var_value);
ofslen = ofs->stlen;
for (i = NF; i > 0; i--) {
tmp = fields_arr[i];
tmp = force_string(tmp);
tlen += tmp->stlen;
}
tlen += (NF - 1) * ofslen;
if ((long) tlen < 0)
tlen = 0;
emalloc(ops, char *, tlen + 2, "rebuild_record");
cops = ops;
ops[0] = '\0';
for (i = 1; i <= NF; i++) {
tmp = fields_arr[i];
/* copy field */
if (tmp->stlen == 1)
*cops++ = tmp->stptr[0];
else if (tmp->stlen != 0) {
memcpy(cops, tmp->stptr, tmp->stlen);
cops += tmp->stlen;
}
/* copy OFS */
if (i != NF) {
if (ofslen == 1)
*cops++ = ofs->stptr[0];
else if (ofslen != 0) {
memcpy(cops, ofs->stptr, ofslen);
cops += ofslen;
}
}
}
tmp = make_str_node(ops, tlen, ALREADY_MALLOCED);
/*
* Since we are about to unref fields_arr[0], we want to find
* any fields that still point into it, and have them point
* into the new field zero.
*/
f0start = fields_arr[0]->stptr;
f0end = fields_arr[0]->stptr + fields_arr[0]->stlen;
for (cops = ops, i = 1; i <= NF; i++) {
char *field_data = fields_arr[i]->stptr;
if (fields_arr[i]->stlen > 0
&& f0start <= field_data && field_data < f0end)
fields_arr[i]->stptr = cops;
cops += fields_arr[i]->stlen + ofslen;
}
unref(fields_arr[0]);
fields_arr[0] = tmp;
field0_valid = TRUE;
}
/*
* set_record:
* setup $0, but defer parsing rest of line until reference is made to $(>0)
* or to NF. At that point, parse only as much as necessary.
*/
void
set_record(buf, cnt, freeold)
char *buf; /* ignored if ! freeold */
int cnt; /* ignored if ! freeold */
int freeold;
{
register int i;
NODE *n;
NF = -1;
for (i = 1; i <= parse_high_water; i++) {
unref(fields_arr[i]);
getnode(n);
*n = *Null_field;
fields_arr[i] = n;
}
parse_high_water = 0;
/*
* $0 = $0 should resplit using the current value of FS, thus,
* this is executed orthogonally to the value of freeold.
*/
if (resave_fs) {
resave_fs = FALSE;
unref(save_FS);
save_FS = dupnode(FS_node->var_value);
}
if (freeold) {
unref(fields_arr[0]);
getnode(n);
n->stptr = buf;
n->stlen = cnt;
n->stref = 1;
n->type = Node_val;
n->stfmt = -1;
n->flags = (STRING|STR|MAYBE_NUM|SCALAR|FIELD);
fields_arr[0] = n;
}
fields_arr[0]->flags |= MAYBE_NUM;
field0_valid = TRUE;
}
/* reset_record --- start over again with current $0 */
void
reset_record()
{
(void) force_string(fields_arr[0]);
set_record(fields_arr[0]->stptr, fields_arr[0]->stlen, FALSE);
}
/* set_NF --- handle what happens to $0 and fields when NF is changed */
void
set_NF()
{
register int i;
NODE *n;
assert(NF != -1);
NF = (long) force_number(NF_node->var_value);
if (NF > nf_high_water)
grow_fields_arr(NF);
if (parse_high_water < NF) {
for (i = parse_high_water + 1; i <= NF; i++) {
unref(fields_arr[i]);
getnode(n);
*n = *Null_field;
fields_arr[i] = n;
}
} else if (parse_high_water > 0) {
for (i = NF + 1; i <= parse_high_water; i++) {
unref(fields_arr[i]);
getnode(n);
*n = *Null_field;
fields_arr[i] = n;
}
parse_high_water = NF;
}
field0_valid = FALSE;
}
/*
* re_parse_field --- parse fields using a regexp.
*
* This is called both from get_field() and from do_split()
* via (*parse_field)(). This variation is for when FS is a regular
* expression -- either user-defined or because RS=="" and FS==" "
*/
static long
re_parse_field(up_to, buf, len, fs, rp, set, n)
long up_to; /* parse only up to this field number */
char **buf; /* on input: string to parse; on output: point to start next */
int len;
NODE *fs;
Regexp *rp;
Setfunc set; /* routine to set the value of the parsed field */
NODE *n;
{
register char *scan = *buf;
register long nf = parse_high_water;
register char *field;
register char *end = scan + len;
if (up_to == HUGE)
nf = 0;
if (len == 0)
return nf;
if (RS_is_null && default_FS)
while (scan < end && (*scan == ' ' || *scan == '\t' || *scan == '\n'))
scan++;
field = scan;
while (scan < end
&& research(rp, scan, 0, (end - scan), TRUE) != -1
&& nf < up_to) {
if (REEND(rp, scan) == RESTART(rp, scan)) { /* null match */
scan++;
if (scan == end) {
(*set)(++nf, field, (long)(scan - field), n);
up_to = nf;
break;
}
continue;
}
(*set)(++nf, field,
(long)(scan + RESTART(rp, scan) - field), n);
scan += REEND(rp, scan);
field = scan;
if (scan == end) /* FS at end of record */
(*set)(++nf, field, 0L, n);
}
if (nf != up_to && scan < end) {
(*set)(++nf, scan, (long)(end - scan), n);
scan = end;
}
*buf = scan;
return (nf);
}
/*
* def_parse_field --- default field parsing.
*
* This is called both from get_field() and from do_split()
* via (*parse_field)(). This variation is for when FS is a single space
* character.
*/
static long
def_parse_field(up_to, buf, len, fs, rp, set, n)
long up_to; /* parse only up to this field number */
char **buf; /* on input: string to parse; on output: point to start next */
int len;
NODE *fs;
Regexp *rp;
Setfunc set; /* routine to set the value of the parsed field */
NODE *n;
{
register char *scan = *buf;
register long nf = parse_high_water;
register char *field;
register char *end = scan + len;
char sav;
if (up_to == HUGE)
nf = 0;
if (len == 0)
return nf;
/*
* Nasty special case. If FS set to "", return whole record
* as first field. This is not worth a separate function.
*/
if (fs->stlen == 0) {
(*set)(++nf, *buf, len, n);
*buf += len;
return nf;
}
/* before doing anything save the char at *end */
sav = *end;
/* because it will be destroyed now: */
*end = ' '; /* sentinel character */
for (; nf < up_to; scan++) {
/*
* special case: fs is single space, strip leading whitespace
*/
while (scan < end && (*scan == ' ' || *scan == '\t' || *scan == '\n'))
scan++;
if (scan >= end)
break;
field = scan;
while (*scan != ' ' && *scan != '\t' && *scan != '\n')
scan++;
(*set)(++nf, field, (long)(scan - field), n);
if (scan == end)
break;
}
/* everything done, restore original char at *end */
*end = sav;
*buf = scan;
return nf;
}
/*
* posix_def_parse_field --- default field parsing.
*
* This is called both from get_field() and from do_split()
* via (*parse_field)(). This variation is for when FS is a single space
* character. The only difference between this and def_parse_field()
* is that this one does not allow newlines to separate fields.
*/
static long
posix_def_parse_field(up_to, buf, len, fs, rp, set, n)
long up_to; /* parse only up to this field number */
char **buf; /* on input: string to parse; on output: point to start next */
int len;
NODE *fs;
Regexp *rp;
Setfunc set; /* routine to set the value of the parsed field */
NODE *n;
{
register char *scan = *buf;
register long nf = parse_high_water;
register char *field;
register char *end = scan + len;
char sav;
if (up_to == HUGE)
nf = 0;
if (len == 0)
return nf;
/*
* Nasty special case. If FS set to "", return whole record
* as first field. This is not worth a separate function.
*/
if (fs->stlen == 0) {
(*set)(++nf, *buf, len, n);
*buf += len;
return nf;
}
/* before doing anything save the char at *end */
sav = *end;
/* because it will be destroyed now: */
*end = ' '; /* sentinel character */
for (; nf < up_to; scan++) {
/*
* special case: fs is single space, strip leading whitespace
*/
while (scan < end && (*scan == ' ' || *scan == '\t'))
scan++;
if (scan >= end)
break;
field = scan;
while (*scan != ' ' && *scan != '\t')
scan++;
(*set)(++nf, field, (long)(scan - field), n);
if (scan == end)
break;
}
/* everything done, restore original char at *end */
*end = sav;
*buf = scan;
return nf;
}
/*
* null_parse_field --- each character is a separate field
*
* This is called both from get_field() and from do_split()
* via (*parse_field)(). This variation is for when FS is the null string.
*/
static long
null_parse_field(up_to, buf, len, fs, rp, set, n)
long up_to; /* parse only up to this field number */
char **buf; /* on input: string to parse; on output: point to start next */
int len;
NODE *fs;
Regexp *rp;
Setfunc set; /* routine to set the value of the parsed field */
NODE *n;
{
register char *scan = *buf;
register long nf = parse_high_water;
register char *end = scan + len;
if (up_to == HUGE)
nf = 0;
if (len == 0)
return nf;
for (; nf < up_to && scan < end; scan++)
(*set)(++nf, scan, 1L, n);
*buf = scan;
return nf;
}
/*
* sc_parse_field --- single character field separator
*
* This is called both from get_field() and from do_split()
* via (*parse_field)(). This variation is for when FS is a single character
* other than space.
*/
static long
sc_parse_field(up_to, buf, len, fs, rp, set, n)
long up_to; /* parse only up to this field number */
char **buf; /* on input: string to parse; on output: point to start next */
int len;
NODE *fs;
Regexp *rp;
Setfunc set; /* routine to set the value of the parsed field */
NODE *n;
{
register char *scan = *buf;
register char fschar;
register long nf = parse_high_water;
register char *field;
register char *end = scan + len;
int onecase;
char sav;
if (up_to == HUGE)
nf = 0;
if (len == 0)
return nf;
if (RS_is_null && fs->stlen == 0)
fschar = '\n';
else
fschar = fs->stptr[0];
onecase = (IGNORECASE && isalpha(fschar));
if (onecase)
fschar = casetable[(int) fschar];
/* before doing anything save the char at *end */
sav = *end;
/* because it will be destroyed now: */
*end = fschar; /* sentinel character */
for (; nf < up_to;) {
field = scan;
if (onecase) {
while (casetable[(int) *scan] != fschar)
scan++;
} else {
while (*scan != fschar)
scan++;
}
(*set)(++nf, field, (long)(scan - field), n);
if (scan == end)
break;
scan++;
if (scan == end) { /* FS at end of record */
(*set)(++nf, field, 0L, n);
break;
}
}
/* everything done, restore original char at *end */
*end = sav;
*buf = scan;
return nf;
}
/*
* fw_parse_field --- field parsing using FIELDWIDTHS spec
*
* This is called both from get_field() and from do_split()
* via (*parse_field)(). This variation is for fields are fixed widths.
*/
static long
fw_parse_field(up_to, buf, len, fs, rp, set, n)
long up_to; /* parse only up to this field number */
char **buf; /* on input: string to parse; on output: point to start next */
int len;
NODE *fs;
Regexp *rp;
Setfunc set; /* routine to set the value of the parsed field */
NODE *n;
{
register char *scan = *buf;
register long nf = parse_high_water;
register char *end = scan + len;
if (up_to == HUGE)
nf = 0;
if (len == 0)
return nf;
for (; nf < up_to && (len = FIELDWIDTHS[nf+1]) != -1; ) {
if (len > end - scan)
len = end - scan;
(*set)(++nf, scan, (long) len, n);
scan += len;
}
if (len == -1)
*buf = end;
else
*buf = scan;
return nf;
}
/* get_field --- return a particular $n */
NODE **
get_field(requested, assign)
register long requested;
Func_ptr *assign; /* this field is on the LHS of an assign */
{
/*
* if requesting whole line but some other field has been altered,
* then the whole line must be rebuilt
*/
if (requested == 0) {
if (! field0_valid) {
/* first, parse remainder of input record */
if (NF == -1) {
NF = (*parse_field)(HUGE-1, &parse_extent,
fields_arr[0]->stlen -
(parse_extent - fields_arr[0]->stptr),
save_FS, FS_regexp, set_field,
(NODE *) NULL);
parse_high_water = NF;
}
rebuild_record();
}
if (assign != NULL)
*assign = reset_record;
return &fields_arr[0];
}
/* assert(requested > 0); */
if (assign != NULL)
field0_valid = FALSE; /* $0 needs reconstruction */
if (requested <= parse_high_water) /* already parsed this field */
return &fields_arr[requested];
if (NF == -1) { /* have not yet parsed to end of record */
/*
* parse up to requested fields, calling set_field() for each,
* saving in parse_extent the point where the parse left off
*/
if (parse_high_water == 0) /* starting at the beginning */
parse_extent = fields_arr[0]->stptr;
parse_high_water = (*parse_field)(requested, &parse_extent,
fields_arr[0]->stlen - (parse_extent - fields_arr[0]->stptr),
save_FS, FS_regexp, set_field, (NODE *) NULL);
/*
* if we reached the end of the record, set NF to the number of
* fields so far. Note that requested might actually refer to
* a field that is beyond the end of the record, but we won't
* set NF to that value at this point, since this is only a
* reference to the field and NF only gets set if the field
* is assigned to -- this case is handled below
*/
if (parse_extent == fields_arr[0]->stptr + fields_arr[0]->stlen)
NF = parse_high_water;
if (requested == HUGE-1) /* HUGE-1 means set NF */
requested = parse_high_water;
}
if (parse_high_water < requested) { /* requested beyond end of record */
if (assign != NULL) { /* expand record */
if (requested > nf_high_water)
grow_fields_arr(requested);
NF = requested;
parse_high_water = requested;
} else
return &Null_field;
}
return &fields_arr[requested];
}
/* set_element --- set an array element, used by do_split() */
static void
set_element(num, s, len, n)
long num;
char *s;
long len;
NODE *n;
{
register NODE *it;
it = make_string(s, len);
it->flags |= MAYBE_NUM;
*assoc_lookup(n, tmp_number((AWKNUM) (num))) = it;
}
/* do_split --- implement split(), semantics are same as for field splitting */
NODE *
do_split(tree)
NODE *tree;
{
NODE *src, *arr, *sep, *tmp;
NODE *fs;
char *s;
long (*parseit) P((long, char **, int, NODE *,
Regexp *, Setfunc, NODE *));
Regexp *rp = NULL;
/*
* do dupnode(), to avoid problems like
* x = split(a[1], a, "blah")
* since we assoc_clear the array. gack.
* this also gives us complete call by value semantics.
*/
tmp = tree_eval(tree->lnode);
src = dupnode(tmp);
free_temp(tmp);
arr = tree->rnode->lnode;
if (tree->rnode->rnode != NULL)
sep = tree->rnode->rnode->lnode; /* 3rd arg */
else
sep = NULL;
(void) force_string(src);
if (arr->type == Node_param_list)
arr = stack_ptr[arr->param_cnt];
if (arr->type != Node_var && arr->type != Node_var_array)
fatal("second argument of split is not an array");
arr->type = Node_var_array;
assoc_clear(arr);
if (sep->re_flags & FS_DFLT) {
parseit = parse_field;
fs = force_string(FS_node->var_value);
rp = FS_regexp;
} else {
tmp = force_string(tree_eval(sep->re_exp));
if (tmp->stlen == 0)
parseit = null_parse_field;
else if (tmp->stlen == 1 && (sep->re_flags & CONST) == 0) {
if (tmp->stptr[0] == ' ') {
if (do_posix)
parseit = posix_def_parse_field;
else
parseit = def_parse_field;
} else
parseit = sc_parse_field;
} else {
parseit = re_parse_field;
rp = re_update(sep);
}
fs = tmp;
}
s = src->stptr;
tmp = tmp_number((AWKNUM) (*parseit)(HUGE, &s, (int) src->stlen,
fs, rp, set_element, arr));
unref(src);
free_temp(sep);
return tmp;
}
/* set_FIELDWIDTHS --- handle an assignment to FIELDWIDTHS */
void
set_FIELDWIDTHS()
{
register char *scan;
char *end;
register int i;
static int fw_alloc = 1;
static int warned = FALSE;
extern double strtod();
if (do_lint && ! warned) {
warned = TRUE;
warning("use of FIELDWIDTHS is a gawk extension");
}
if (do_traditional) /* quick and dirty, does the trick */
return;
/*
* If changing the way fields are split, obey least-suprise
* semantics, and force $0 to be split totally.
*/
if (fields_arr != NULL)
(void) get_field(HUGE - 1, 0);
parse_field = fw_parse_field;
scan = force_string(FIELDWIDTHS_node->var_value)->stptr;
end = scan + 1;
if (FIELDWIDTHS == NULL)
emalloc(FIELDWIDTHS, int *, fw_alloc * sizeof(int), "set_FIELDWIDTHS");
FIELDWIDTHS[0] = 0;
for (i = 1; ; i++) {
if (i >= fw_alloc) {
fw_alloc *= 2;
erealloc(FIELDWIDTHS, int *, fw_alloc * sizeof(int), "set_FIELDWIDTHS");
}
FIELDWIDTHS[i] = (int) strtod(scan, &end);
if (end == scan)
break;
scan = end;
}
FIELDWIDTHS[i] = -1;
}
void
set_FS_if_not_FIELDWIDTHS()
{
if (parse_field != fw_parse_field)
set_FS();
}
/* set_FS --- handle things when FS is assigned to */
void
set_FS()
{
char buf[10];
NODE *fs;
static NODE *save_fs = NULL;
static NODE *save_rs = NULL;
/*
* If changing the way fields are split, obey least-suprise
* semantics, and force $0 to be split totally.
*/
if (fields_arr != NULL)
(void) get_field(HUGE - 1, 0);
if (save_fs && cmp_nodes(FS_node->var_value, save_fs) == 0
&& save_rs && cmp_nodes(RS_node->var_value, save_rs) == 0)
return;
unref(save_fs);
save_fs = dupnode(FS_node->var_value);
unref(save_rs);
save_rs = dupnode(RS_node->var_value);
resave_fs = TRUE;
buf[0] = '\0';
default_FS = FALSE;
if (FS_regexp) {
refree(FS_regexp);
FS_regexp = NULL;
}
fs = force_string(FS_node->var_value);
if (! do_traditional && fs->stlen == 0)
parse_field = null_parse_field;
else if (fs->stlen > 1)
parse_field = re_parse_field;
else if (RS_is_null) {
parse_field = sc_parse_field;
if (fs->stlen == 1) {
if (fs->stptr[0] == ' ') {
default_FS = TRUE;
strcpy(buf, "[ \t\n]+");
} else if (fs->stptr[0] != '\n')
sprintf(buf, "[%c\n]", fs->stptr[0]);
}
} else {
if (do_posix)
parse_field = posix_def_parse_field;
else
parse_field = def_parse_field;
if (fs->stptr[0] == ' ' && fs->stlen == 1)
default_FS = TRUE;
else if (fs->stptr[0] != ' ' && fs->stlen == 1) {
if (! IGNORECASE)
parse_field = sc_parse_field;
else if (fs->stptr[0] == '\\')
/* yet another special case */
strcpy(buf, "[\\\\]");
else
sprintf(buf, "[%c]", fs->stptr[0]);
}
}
if (buf[0] != '\0') {
FS_regexp = make_regexp(buf, strlen(buf), IGNORECASE, TRUE);
parse_field = re_parse_field;
} else if (parse_field == re_parse_field) {
FS_regexp = make_regexp(fs->stptr, fs->stlen, IGNORECASE, TRUE);
} else
FS_regexp = NULL;
}
/* using_fieldwidths --- is FS or FIELDWIDTHS in use? */
int
using_fieldwidths()
{
return parse_field == fw_parse_field;
}
