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4.4BSD snapshot (revision 8.1); add 1993 to copyright
[unix-history] / usr / src / usr.bin / sed / process.c
/*-
* Copyright (c) 1992 Diomidis Spinellis.
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Diomidis Spinellis of Imperial College, University of London.
*
* %sccs.include.redist.c%
*/
#ifndef lint
static char sccsid[] = "@(#)process.c 8.1 (Berkeley) %G%";
#endif /* not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/uio.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "defs.h"
#include "extern.h"
static SPACE HS, PS, SS;
#define pd PS.deleted
#define ps PS.space
#define psl PS.len
#define hs HS.space
#define hsl HS.len
static inline int applies __P((struct s_command *));
static void flush_appends __P((void));
static void lputs __P((char *));
static inline int regexec_e __P((regex_t *, const char *, int, int, size_t));
static void regsub __P((SPACE *, char *, char *));
static int substitute __P((struct s_command *));
struct s_appends *appends; /* Array of pointers to strings to append. */
static int appendx; /* Index into appends array. */
int appendnum; /* Size of appends array. */
static int lastaddr; /* Set by applies if last address of a range. */
static int sdone; /* If any substitutes since last line input. */
/* Iov structure for 'w' commands. */
static regex_t *defpreg;
size_t maxnsub;
regmatch_t *match;
#define OUT(s) { fwrite(s, sizeof(u_char), psl, stdout); }
void
process()
{
struct s_command *cp;
SPACE tspace;
size_t len;
int r;
char oldc, *p;
for (linenum = 0; mf_fgets(&PS, REPLACE);) {
pd = 0;
cp = prog;
redirect:
while (cp != NULL) {
if (!applies(cp)) {
cp = cp->next;
continue;
}
switch (cp->code) {
case '{':
cp = cp->u.c;
goto redirect;
case 'a':
if (appendx >= appendnum)
appends = xrealloc(appends,
sizeof(struct s_appends) *
(appendnum *= 2));
appends[appendx].type = AP_STRING;
appends[appendx].s = cp->t;
appends[appendx].len = strlen(cp->t);
appendx++;
break;
case 'b':
cp = cp->u.c;
goto redirect;
case 'c':
pd = 1;
psl = 0;
if (cp->a2 == NULL || lastaddr)
(void)printf("%s", cp->t);
break;
case 'd':
pd = 1;
goto new;
case 'D':
if (pd)
goto new;
if ((p = memchr(ps, '\n', psl)) == NULL)
pd = 1;
else {
psl -= (p - ps) - 1;
memmove(ps, p + 1, psl);
}
goto new;
case 'g':
cspace(&PS, hs, hsl, REPLACE);
break;
case 'G':
cspace(&PS, hs, hsl, 0);
break;
case 'h':
cspace(&HS, ps, psl, REPLACE);
break;
case 'H':
cspace(&HS, ps, psl, 0);
break;
case 'i':
(void)printf("%s", cp->t);
break;
case 'l':
lputs(ps);
break;
case 'n':
if (!nflag && !pd)
OUT(ps)
flush_appends();
r = mf_fgets(&PS, REPLACE);
#ifdef HISTORIC_PRACTICE
if (!r)
exit(0);
#endif
pd = 0;
break;
case 'N':
flush_appends();
if (!mf_fgets(&PS, 0)) {
if (!nflag && !pd)
OUT(ps)
exit(0);
}
break;
case 'p':
if (pd)
break;
OUT(ps)
break;
case 'P':
if (pd)
break;
if ((p = memchr(ps, '\n', psl)) != NULL) {
oldc = *p;
*p = '\0';
}
OUT(ps)
if (p != NULL)
*p = oldc;
break;
case 'q':
if (!nflag && !pd)
OUT(ps)
flush_appends();
exit(0);
case 'r':
if (appendx >= appendnum)
appends = xrealloc(appends,
sizeof(struct s_appends) *
(appendnum *= 2));
appends[appendx].type = AP_FILE;
appends[appendx].s = cp->t;
appends[appendx].len = strlen(cp->t);
appendx++;
break;
case 's':
sdone |= substitute(cp);
break;
case 't':
if (sdone) {
sdone = 0;
cp = cp->u.c;
goto redirect;
}
break;
case 'w':
if (pd)
break;
if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
DEFFILEMODE)) == -1)
err(FATAL, "%s: %s\n",
cp->t, strerror(errno));
if (write(cp->u.fd, ps, psl) != psl)
err(FATAL, "%s: %s\n",
cp->t, strerror(errno));
break;
case 'x':
if (hs == NULL)
cspace(&HS, "", 0, REPLACE);
tspace = PS;
PS = HS;
HS = tspace;
break;
case 'y':
if (pd)
break;
for (p = ps, len = psl; --len; ++p)
*p = cp->u.y[*p];
break;
case ':':
case '}':
break;
case '=':
(void)printf("%lu\n", linenum);
}
cp = cp->next;
} /* for all cp */
new: if (!nflag && !pd)
OUT(ps)
flush_appends();
} /* for all lines */
}
/*
* TRUE if the address passed matches the current program state
* (lastline, linenumber, ps).
*/
#define MATCH(a) \
(a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) : \
(a)->type == AT_LINE ? linenum == (a)->u.l : lastline
/*
* Return TRUE if the command applies to the current line. Sets the inrange
* flag to process ranges. Interprets the non-select (``!'') flag.
*/
static inline int
applies(cp)
struct s_command *cp;
{
int r;
lastaddr = 0;
if (cp->a1 == NULL && cp->a2 == NULL)
r = 1;
else if (cp->a2)
if (cp->inrange) {
if (MATCH(cp->a2)) {
cp->inrange = 0;
lastaddr = 1;
}
r = 1;
} else if (MATCH(cp->a1)) {
/*
* If the second address is a number less than or
* equal to the line number first selected, only
* one line shall be selected.
* -- POSIX 1003.2
*/
if (cp->a2->type == AT_LINE &&
linenum >= cp->a2->u.l)
lastaddr = 1;
else
cp->inrange = 1;
r = 1;
} else
r = 0;
else
r = MATCH(cp->a1);
return (cp->nonsel ? ! r : r);
}
/*
* substitute --
* Do substitutions in the pattern space. Currently, we build a
* copy of the new pattern space in the substitute space structure
* and then swap them.
*/
static int
substitute(cp)
struct s_command *cp;
{
SPACE tspace;
regex_t *re;
size_t re_off, slen;
int n;
char *s;
s = ps;
re = cp->u.s->re;
if (re == NULL) {
if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
linenum = cp->u.s->linenum;
err(COMPILE, "\\%d not defined in the RE",
cp->u.s->maxbref);
}
}
if (!regexec_e(re, s, 0, 0, psl))
return (0);
SS.len = 0; /* Clean substitute space. */
slen = psl;
n = cp->u.s->n;
switch (n) {
case 0: /* Global */
do {
/* Locate start of replaced string. */
re_off = match[0].rm_so;
/* Copy leading retained string. */
cspace(&SS, s, re_off, APPEND);
/* Add in regular expression. */
regsub(&SS, s, cp->u.s->new);
/* Move past this match. */
s += match[0].rm_eo;
slen -= match[0].rm_eo;
} while(regexec_e(re, s, REG_NOTBOL, 0, slen));
/* Copy trailing retained string. */
cspace(&SS, s, slen, APPEND);
break;
default: /* Nth occurrence */
while (--n) {
s += match[0].rm_eo;
slen -= match[0].rm_eo;
if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
return (0);
}
/* FALLTHROUGH */
case 1: /* 1st occurrence */
/* Locate start of replaced string. */
re_off = match[0].rm_so + (s - ps);
/* Copy leading retained string. */
cspace(&SS, ps, re_off, APPEND);
/* Add in regular expression. */
regsub(&SS, s, cp->u.s->new);
/* Copy trailing retained string. */
s += match[0].rm_eo;
slen -= match[0].rm_eo;
cspace(&SS, s, slen, APPEND);
break;
}
/*
* Swap the substitute space and the pattern space, and make sure
* that any leftover pointers into stdio memory get lost.
*/
tspace = PS;
PS = SS;
SS = tspace;
SS.space = SS.back;
/* Handle the 'p' flag. */
if (cp->u.s->p)
OUT(ps)
/* Handle the 'w' flag. */
if (cp->u.s->wfile && !pd) {
if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
if (write(cp->u.s->wfd, ps, psl) != psl)
err(FATAL, "%s: %s\n", cp->u.s->wfile, strerror(errno));
}
return (1);
}
/*
* Flush append requests. Always called before reading a line,
* therefore it also resets the substitution done (sdone) flag.
*/
static void
flush_appends()
{
FILE *f;
int count, i;
char buf[8 * 1024];
for (i = 0; i < appendx; i++)
switch (appends[i].type) {
case AP_STRING:
fwrite(appends[i].s, sizeof(char), appends[i].len,
stdout);
break;
case AP_FILE:
/*
* Read files probably shouldn't be cached. Since
* it's not an error to read a non-existent file,
* it's possible that another program is interacting
* with the sed script through the file system. It
* would be truly bizarre, but possible. It's probably
* not that big a performance win, anyhow.
*/
if ((f = fopen(appends[i].s, "r")) == NULL)
break;
while (count = fread(buf, sizeof(char), sizeof(buf), f))
(void)fwrite(buf, sizeof(char), count, stdout);
(void)fclose(f);
break;
}
if (ferror(stdout))
err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
appendx = sdone = 0;
}
static void
lputs(s)
register char *s;
{
register int count;
register char *escapes, *p;
struct winsize win;
static int termwidth = -1;
if (termwidth == -1)
if (p = getenv("COLUMNS"))
termwidth = atoi(p);
else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
win.ws_col > 0)
termwidth = win.ws_col;
else
termwidth = 60;
for (count = 0; *s; ++s) {
if (count >= termwidth) {
(void)printf("\\\n");
count = 0;
}
if (isascii(*s) && isprint(*s) && *s != '\\') {
(void)putchar(*s);
count++;
} else {
escapes = "\\\a\b\f\n\r\t\v";
(void)putchar('\\');
if (p = strchr(escapes, *s)) {
(void)putchar("\\abfnrtv"[p - escapes]);
count += 2;
} else {
(void)printf("%03o", *(u_char *)s);
count += 4;
}
}
}
(void)putchar('$');
(void)putchar('\n');
if (ferror(stdout))
err(FATAL, "stdout: %s", strerror(errno ? errno : EIO));
}
static inline int
regexec_e(preg, string, eflags, nomatch, slen)
regex_t *preg;
const char *string;
int eflags, nomatch;
size_t slen;
{
int eval;
if (preg == NULL) {
if (defpreg == NULL)
err(FATAL, "first RE may not be empty");
} else
defpreg = preg;
/* Set anchors, discounting trailing newline (if any). */
if (slen > 0 && string[slen - 1] == '\n')
slen--;
match[0].rm_so = 0;
match[0].rm_eo = slen;
eval = regexec(defpreg, string,
nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
switch(eval) {
case 0:
return (1);
case REG_NOMATCH:
return (0);
}
err(FATAL, "RE error: %s", strregerror(eval, defpreg));
/* NOTREACHED */
}
/*
* regsub - perform substitutions after a regexp match
* Based on a routine by Henry Spencer
*/
static void
regsub(sp, string, src)
SPACE *sp;
char *string, *src;
{
register int len, no;
register char c, *dst;
#define NEEDSP(reqlen) \
if (sp->len >= sp->blen - (reqlen) - 1) { \
sp->blen += (reqlen) + 1024; \
sp->space = sp->back = xrealloc(sp->back, sp->blen); \
dst = sp->space + sp->len; \
}
dst = sp->space + sp->len;
while ((c = *src++) != '\0') {
if (c == '&')
no = 0;
else if (c == '\\' && isdigit(*src))
no = *src++ - '0';
else
no = -1;
if (no < 0) { /* Ordinary character. */
if (c == '\\' && (*src == '\\' || *src == '&'))
c = *src++;
NEEDSP(1);
*dst++ = c;
++sp->len;
} else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
len = match[no].rm_eo - match[no].rm_so;
NEEDSP(len);
memmove(dst, string + match[no].rm_so, len);
dst += len;
sp->len += len;
}
}
NEEDSP(1);
*dst = '\0';
}
/*
* aspace --
* Append the source space to the destination space, allocating new
* space as necessary.
*/
void
cspace(sp, p, len, spflag)
SPACE *sp;
char *p;
size_t len;
enum e_spflag spflag;
{
size_t tlen;
/* Make sure SPACE has enough memory and ramp up quickly. */
tlen = sp->len + len + 1;
if (tlen > sp->blen) {
sp->blen = tlen + 1024;
sp->space = sp->back = xrealloc(sp->back, sp->blen);
}
if (spflag == REPLACE)
sp->len = 0;
memmove(sp->space + sp->len, p, len);
sp->space[sp->len += len] = '\0';
}
/*
* Close all cached opened files and report any errors
*/
void
cfclose(cp, end)
register struct s_command *cp, *end;
{
for (; cp != end; cp = cp->next)
switch(cp->code) {
case 's':
if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
err(FATAL,
"%s: %s", cp->u.s->wfile, strerror(errno));
cp->u.s->wfd = -1;
break;
case 'w':
if (cp->u.fd != -1 && close(cp->u.fd))
err(FATAL, "%s: %s", cp->t, strerror(errno));
cp->u.fd = -1;
break;
case '{':
cfclose(cp->u.c, cp->next);
break;
}
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.