ref: a411870ee4640241e3c494367d922847da84f972
dir: purgatorio/appl/cmd/sed.b
implement Sed;
#
# partial sed implementation borrowed from plan9 sed.
#
include "sys.m";
sys: Sys;
include "draw.m";
include "arg.m";
arg: Arg;
include "bufio.m";
bufio: Bufio;
Iobuf: import bufio;
include "string.m";
str: String;
include "regex.m";
regex: Regex;
Re: import regex;
Sed : module {
init: fn(ctxt: ref Draw->Context, argv: list of string);
};
false, true: con iota;
bool: type int;
Addr: adt {
pick {
None =>
Dollar =>
Line =>
line: int;
Regex =>
re: Re;
}
};
Sedcom: adt {
command: fn(c: self ref Sedcom);
executable: fn(c: self ref Sedcom) : int;
ad1, ad2: ref Addr;
negfl: bool;
active: int;
pick {
S =>
gfl, pfl: int;
re: Re;
b: ref Iobuf;
rhs: string;
D or CD or P or Q or EQ or G or CG or H or CH or N or CN or X or CP or L=>
A or C or I =>
text: string;
R =>
filename: string;
W =>
b: ref Iobuf;
Y =>
map: list of (int, int);
B or T or Lab =>
lab: string;
}
};
dflag := false;
nflag := false;
gflag := false;
sflag := 0;
delflag := 0;
dolflag := 0;
fhead := 0;
files: list of string;
fout: ref Iobuf;
infile: ref Iobuf;
jflag := 0;
lastregex: Re;
linebuf: string;
filename := "";
lnum := 0;
peekc := 0;
holdsp := "";
patsp := "";
cmds: list of ref Sedcom;
appendlist: list of ref Sedcom;
bufioflush: list of ref Iobuf;
init(nil: ref Draw->Context, args: list of string)
{
sys = load Sys Sys->PATH;
if ((arg = load Arg Arg->PATH) == nil)
fatal(sys->sprint("could not load %s: %r", Arg->PATH));
if ((bufio = load Bufio Bufio->PATH) == nil)
fatal(sys->sprint("could not load %s: %r", Bufio->PATH));
if ((str = load String String->PATH) == nil)
fatal(sys->sprint("could not load %s: %r", String->PATH));
if ((regex = load Regex Regex->PATH) == nil)
fatal(sys->sprint("could not load %s: %r", Regex->PATH));
arg->init(args);
compfl := 0;
while ((c := arg->opt()) != 0)
case c {
'n' =>
nflag = true;
'g' =>
gflag = true;
'e' =>
if ((s := arg->arg()) == nil)
usage();
filename = "";
cmds = compile(bufio->sopen(s + "\n"), cmds);
compfl = 1;
'f' => if ((filename = arg->arg()) == nil)
usage();
b := bufio->open(filename, bufio->OREAD);
if (b == nil)
fatal(sys->sprint("couldn't open '%s': %r", filename));
cmds = compile(b, cmds);
compfl = 1;
'd' =>
dflag = true;
* =>
usage();
}
args = arg->argv();
if (compfl == 0) {
if (len args == 0)
fatal("missing pattern");
filename = "";
cmds = compile(bufio->sopen(hd args + "\n"), cmds);
args = tl args;
}
# reverse command list, we could compile addresses here if required
l: list of ref Sedcom;
for (p := cmds; p != nil; p = tl p) {
l = hd p :: l;
}
cmds = l;
# add files to file list (and reverse to get in right order)
f: list of string;
if (len args == 0)
f = "" :: f;
else for (; len args != 0; args = tl args)
f = hd args :: f;
for (;f != nil; f = tl f)
files = hd f :: files;
if ((fout = bufio->fopen(sys->fildes(1), bufio->OWRITE)) == nil)
fatal(sys->sprint("couldn't buffer stdout: %r"));
bufioflush = fout :: bufioflush;
lnum = 0;
execute(cmds);
exits(nil);
}
depth := 0;
maxdepth: con 20;
cmdend := array [maxdepth] of string;
cmdcnt := array [maxdepth] of int;
compile(b: ref Iobuf, l: list of ref Sedcom) : list of ref Sedcom
{
lnum = 1;
nextline:
for (;;) {
err: int;
(err, linebuf) = getline(b);
if (err < 0)
break;
s := linebuf;
do {
rep: ref Sedcom;
ad1, ad2: ref Addr;
negfl := 0;
if (s != "")
s = str->drop(s, " \t;");
if (s == "" || s[0] == '#')
continue nextline;
# read addresses
(s, ad1) = address(s);
pick a := ad1 {
None =>
ad2 = ref Addr.None();
* =>
if (s != "" && (s[0] == ',' || s[0] == ';')) {
(s, ad2) = address(s[1:]);
}
else {
ad2 = ref Addr.None();
}
}
s = str->drop(s, " \t");
if (s != "" && str->in(s[0], "!")) {
negfl = true;
s = str->drop(s, "!");
}
s = str->drop(s, " \t");
if (s == "")
break;
c := s[0]; s = s[1:];
# mop up commands that got two addresses but only want one.
case c {
'a' or 'c' or 'q' or '=' or 'i' =>
if (tagof ad2 != tagof Addr.None)
fatal(sys->sprint("only one address allowed: '%s'",
linebuf));
}
case c {
* =>
fatal(sys->sprint("unrecognised command: '%s' (%c)",
linebuf, c));
'a' =>
if (s != "" && s[0] == '\\')
s = s[1:];
if (s == "" || s[0] != '\n')
fatal("unexpected characters in a command: " + s);
rep = ref Sedcom.A (ad1, ad2, negfl, 0, s[1:]);
s = "";
'c' =>
if (s != "" && s[0] == '\\')
s = s[1:];
if (s == "" || s[0] != '\n')
fatal("unexpected characters in c command: " + s);
rep = ref Sedcom.C (ad1, ad2, negfl, 0, s[1:]);
s = "";
'i' =>
if (s != "" && s[0] == '\\')
s = s[1:];
if (s == "" || s[0] != '\n')
fatal("unexpected characters in i command: " + s);
rep = ref Sedcom.I (ad1, ad2, negfl, 0, s[1:]);
s = "";
'r' =>
s = str->drop(s, " \t");
rep = ref Sedcom.R (ad1, ad2, negfl, 0, s);
s = "";
'w' =>
if (s != "")
s = str->drop(s, " \t");
if (s == "")
fatal("no filename in w command: " + linebuf);
bo := bufio->open(s, bufio->OWRITE);
if (bo == nil)
bo = bufio->create(s, bufio->OWRITE, 8r666);
if (bo == nil)
fatal(sys->sprint("can't create output file: '%s'", s));
bufioflush = bo :: bufioflush;
rep = ref Sedcom.W (ad1, ad2, negfl, 0, bo);
s = "";
'd' =>
rep = ref Sedcom.D (ad1, ad2, negfl, 0);
'D' =>
rep = ref Sedcom.CD (ad1, ad2, negfl, 0);
'p' =>
rep = ref Sedcom.P (ad1, ad2, negfl, 0);
'P' =>
rep = ref Sedcom.CP (ad1, ad2, negfl, 0);
'q' =>
rep = ref Sedcom.Q (ad1, ad2, negfl, 0);
'=' =>
rep = ref Sedcom.EQ (ad1, ad2, negfl, 0);
'g' =>
rep = ref Sedcom.G (ad1, ad2, negfl, 0);
'G' =>
rep = ref Sedcom.CG (ad1, ad2, negfl, 0);
'h' =>
rep = ref Sedcom.H (ad1, ad2, negfl, 0);
'H' =>
rep = ref Sedcom.CH (ad1, ad2, negfl, 0);
'n' =>
rep = ref Sedcom.N (ad1, ad2, negfl, 0);
'N' =>
rep = ref Sedcom.CN (ad1, ad2, negfl, 0);
'x' =>
rep = ref Sedcom.X (ad1, ad2, negfl, 0);
'l' =>
rep = ref Sedcom.L (ad1, ad2, negfl, 0);
'y' =>
if (s == "")
fatal("expected args: " + linebuf);
seof := s[0:1];
s = s[1:];
if (s == "")
fatal("no lhs: " + linebuf);
(lhs, s2) := str->splitl(s, seof);
if (s2 == "")
fatal("no lhs terminator: " + linebuf);
s2 = s2[1:];
(rhs, s4) := str->splitl(s2, seof);
if (s4 == "")
fatal("no rhs: " + linebuf);
s = s4[1:];
if (len lhs != len rhs)
fatal("y command needs same length sets: " + linebuf);
map: list of (int, int);
for (i := 0; i < len lhs; i++)
map = (lhs[i], rhs[i]) :: map;
rep = ref Sedcom.Y (ad1, ad2, negfl, 0, map);
's' =>
seof := s[0:1];
re: Re;
(re, s) = recomp(s);
rhs: string;
(s, rhs) = compsub(seof + s);
gfl := gflag;
pfl := 0;
if (s != "" && s[0] == 'g') {
gfl = 1;
s = s[1:];
}
if (s != "" && s[0] == 'p') {
pfl = 1;
s = s[1:];
}
if (s != "" && s[0] == 'P') {
pfl = 2;
s = s[1:];
}
b: ref Iobuf = nil;
if (s != "" && s[0] == 'w') {
s = s[1:];
if (s != "")
s = str->drop(s, " \t");
if (s == "")
fatal("no filename in s with w: " + linebuf);
b = bufio->open(s, bufio->OWRITE);
if (b == nil)
b = bufio->create(s, bufio->OWRITE, 8r666);
if (b == nil)
fatal(sys->sprint("can't create output file: '%s'", s));
bufioflush = b :: bufioflush;
s = "";
}
rep = ref Sedcom.S (ad1, ad2, negfl, 0, gfl, pfl, re, b, rhs);
':' =>
if (s != "")
s = str->drop(s, " \t");
(lab, s1) := str->splitl(s, " \t;#");
s = s1;
if (lab == "")
fatal(sys->sprint("null label: '%s'", linebuf));
if (findlabel(lab))
fatal(sys->sprint("duplicate label: '%s'", lab));
rep = ref Sedcom.Lab (ad1, ad2, negfl, 0, lab);
'b' or 't' =>
if (s != "")
s = str->drop(s, " \t");
(lab, s1) := str->splitl(s, " \t;#");
s = s1;
if (c == 'b')
rep = ref Sedcom.B (ad1, ad2, negfl, 0, lab);
else
rep = ref Sedcom.T (ad1, ad2, negfl, 0, lab);
'{' =>
# replace { with branch to }.
lab := mklab(depth);
depth++;
rep = ref Sedcom.B (ad1, ad2, !negfl, 0, lab);
s = ";" + s;
'}' =>
if (tagof ad1 != tagof Addr.None)
fatal("did not expect address:" + linebuf);
if (--depth < 0)
fatal("too many }'s: " + linebuf);
lab := mklab(depth);
cmdcnt[depth]++;
rep = ref Sedcom.Lab ( ad1, ad2, negfl, 0, lab);
s = ";" + s;
}
l = rep :: l;
} while (s != nil && str->in(s[0], ";{}"));
if (s != nil)
fatal("leftover junk: " + s);
}
return l;
}
findlabel(lab: string) : bool
{
for (l := cmds; l != nil; l = tl l)
pick x := hd l {
Lab =>
if (x.lab == lab)
return true;
}
return false;
}
mklab(depth: int): string
{
return "_" + string cmdcnt[depth] + "_" + string depth;
}
Sedcom.command(c: self ref Sedcom)
{
pick x := c {
S =>
m: bool;
(m, patsp) = substitute(x, patsp);
if (m) {
case x.pfl {
0 =>
;
1 =>
fout.puts(patsp + "\n");
* =>
l: string;
(l, patsp) = str->splitl(patsp, "\n");
fout.puts(l + "\n");
break;
}
if (x.b != nil)
x.b.puts(patsp + "\n");
}
P =>
fout.puts(patsp + "\n");
CP =>
(s, nil) := str->splitl(patsp, "\n");
fout.puts(s + "\n");
A =>
appendlist = c :: appendlist;
R =>
appendlist = c :: appendlist;
C =>
delflag++;
if (c.active == 1)
fout.puts(x.text + "\n");
I =>
fout.puts(x.text + "\n");
W =>
x.b.puts(patsp + "\n");
G =>
patsp = holdsp;
CG =>
patsp += holdsp;
H =>
holdsp = patsp;
CH =>
holdsp += patsp;
X =>
(holdsp, patsp) = (patsp, holdsp);
Y =>
# yes this is O(N²).
for (i := 0; i < len patsp; i++)
for (h := x.map; h != nil; h = tl h) {
(s, d) := hd h;
if (patsp[i] == s)
patsp[i] = d;
}
D =>
delflag++;
CD =>
# loose upto \n.
(s1, s2) := str->splitl(patsp, "\n");
if (s2 == nil)
patsp = s1;
else if (len s2 > 1)
patsp = s2[1:];
else
patsp = "";
jflag++;
Q =>
if (!nflag)
fout.puts(patsp + "\n");
arout();
exits(nil);
N =>
if (!nflag)
fout.puts(patsp + "\n");
arout();
n: int;
(patsp, n) = gline();
if (n < 0)
delflag++;
CN =>
arout();
(ns, n) := gline();
if (n < 0)
delflag++;
patsp += "\n" + ns;
EQ =>
fout.puts(sys->sprint("%d\n", lnum));
Lab =>
# labels don't do anything.
B =>
jflag = true;
T =>
if (sflag) {
sflag = false;
jflag = true;
}
L =>
col := 0;
cc := 0;
for (i := 0; i < len patsp; i++) {
s := "";
cc = patsp[i];
if (cc >= 16r20 && cc < 16r7F && cc != '\n')
s[len s] = cc;
else
s = trans(cc);
for (j := 0; j < len s; j++) {
fout.putc(s[j]);
if (col++ > 71) {
fout.puts("\\\n");
col = 0;
}
}
}
if (cc == ' ')
fout.puts("\\n");
fout.putc('\n');
* =>
fatal("unhandled command");
}
}
trans(ch: int) : string
{
case ch {
'\b' =>
return "\\b";
'\n' =>
return "\\n";
'\r' =>
return "\\r";
'\t' =>
return "\\t";
'\\' =>
return "\\\\";
* =>
return sys->sprint("\\u%.4ux", ch);
}
}
getline(b: ref Iobuf) : (int, string)
{
w : string;
lnum++;
while ((c := b.getc()) != bufio->EOF) {
r := c;
if (r == '\\') {
w[len w] = r;
if ((c = b.getc()) == bufio->EOF)
break;
r = c;
}
else if (r == '\n')
return (1, w);
w[len w] = r;
}
return (-1, w);
}
address(s: string) : (string, ref Addr)
{
case s[0] {
'$' =>
return (s[1:], ref Addr.Dollar());
'/' =>
(r, s1) := recomp(s);
if (r == nil)
r = lastregex;
if (r == nil)
fatal("First RE in address may not be null");
return (s1, ref Addr.Regex(r));
'0' to '9' =>
(lno, ls) := str->toint(s, 10);
if (lno == 0)
fatal("line no 0 is illegal address");
return (ls, ref Addr.Line(lno));
* =>
return (s, ref Addr.None());
}
}
recomp(s :string) : (Re, string)
{
expbuf := "";
seof := s[0]; s = s[1:];
if (s[0] == seof)
return (nil, s[1:]); # //
c := s[0]; s = s[1:];
do {
if (c == '\0' || c == '\n')
fatal("too much text: " + linebuf);
if (c == '\\') {
expbuf[len expbuf] = c;
c = s[0]; s = s[1:];
if (c == 'n')
c = '\n';
}
expbuf[len expbuf] = c;
c = s[0]; s = s[1:];
} while (c != seof);
(r, err) := regex->compile(expbuf, 1);
if (r == nil)
fatal(sys->sprint("%s '%s'", err, expbuf));
lastregex = r;
return (r, s);
}
compsub(s: string): (string, string)
{
seof := s[0];
rhs := "";
for (i := 1; i < len s; i++) {
r := s[i];
if (r == seof)
break;
if (r == '\\') {
rhs[len rhs] = r;
if(++i >= len s)
break;
r = s[i];
}
rhs[len rhs] = r;
}
if (i >= len s)
fatal(sys->sprint("no closing %c in replacement text: %s", seof, linebuf));
return (s[i+1:], rhs);
}
execute(l: list of ref Sedcom)
{
for (;;) {
n: int;
(patsp, n) = gline();
if (n < 0)
break;
cmdloop:
for (p := l; p != nil;) {
c := hd p;
if (!c.executable()) {
p = tl p;
continue;
}
c.command();
if (delflag)
break;
if (jflag) {
jflag = 0;
pick x := c {
B or T =>
if (p == nil)
break cmdloop;
for (p = l; p != nil; p = tl p) {
pick cc := hd p {
Lab =>
if (cc.lab == x.lab)
continue cmdloop;
}
}
break cmdloop; # unmatched branch => end of script
* =>
# don't branch.
}
}
else
p = tl p;
}
if (!nflag && !delflag)
fout.puts(patsp + "\n");
arout();
delflag = 0;
}
}
Sedcom.executable(c: self ref Sedcom) : int
{
if (c.active) {
if (c.active == 1)
c.active = 2;
pick x := c.ad2 {
None =>
c.active = 0;
Dollar =>
return !c.negfl;
Line =>
if (lnum <= x.line) {
if (x.line == lnum)
c.active = 0;
return !c.negfl;
}
c.active = 0;
return c.negfl;
Regex =>
if (match(x.re, patsp))
c.active = false;
return !c.negfl;
}
}
pick x := c.ad1 {
None =>
return !c.negfl;
Dollar =>
if (dolflag)
return !c.negfl;
Line =>
if (x.line == lnum) {
c.active = 1;
return !c.negfl;
}
Regex =>
if (match(x.re, patsp)) {
c.active = 1;
return !c.negfl;
}
}
return c.negfl;
}
arout()
{
a: list of ref Sedcom;
while (appendlist != nil) {
a = hd appendlist :: a;
appendlist = tl appendlist;
}
for (; a != nil; a = tl a)
pick x := hd a {
A =>
fout.puts(x.text + "\n");
R =>
if ((b := bufio->open(x.filename, bufio->OREAD)) == nil)
fatal(sys->sprint("couldn't open '%s'", x.filename));
while ((c := b.getc()) != bufio->EOF)
fout.putc(c);
b.close();
* =>
fatal("unexpected command on appendlist");
}
}
match(re: Re, s: string) : bool
{
return re != nil && regex->execute(re, s) != nil;
}
substitute(c: ref Sedcom.S, s: string) : (bool, string)
{
if (!match(c.re, s))
return (false, s);
sflag = true;
start := 0;
# Beware of infinite loops: 's/$/i/g', 's/a/aa/g', 's/^/a/g'
do {
se := (start, len s);
if ((m := regex->executese(c.re, s, se, true, true)) == nil)
break;
(l, r) := m[0];
rep := "";
for (i := 0; i < len c.rhs; i++){
if (c.rhs[i] != '\\' || i+1 == len c.rhs){
if (c.rhs[i] == '&')
rep += s[l: r];
else
rep[len rep] = c.rhs[i];
}else {
i++;
case c.rhs[i] {
'0' to '9' =>
n := c.rhs[i] - '0';
# elide if too big
if (n < len m) {
(beg, end) := m[n];
rep += s[beg:end];
}
'n' =>
rep[len rep] = '\n';
* =>
rep[len rep] = c.rhs[i];
}
}
}
s = s[0:l] + rep + s[r:];
start = l + len rep;
if(r == l)
start++;
} while (c.gfl);
return (true, s);
}
gline() : (string, int)
{
if (infile == nil && opendatafile() < 0)
return (nil, -1);
sflag = false;
lnum++;
s := "";
do {
c := peekc;
if (c == 0)
c = infile.getc();
for (; c != bufio->EOF; c = infile.getc()) {
if (c == '\n') {
if ((peekc = infile.getc()) == bufio->EOF)
if (fhead == 0)
dolflag = 1;
return (s, 1);
}
s[len s] = c;
}
if (len s != 0) {
peekc = bufio->EOF;
if (fhead == 0)
dolflag = 1;
return (s, 1);
}
peekc = 0;
infile = nil;
} while (opendatafile() > 0);
infile = nil;
return (nil, -1);
}
opendatafile() : int
{
if (files == nil)
return -1;
if (hd files != nil) {
if ((infile = bufio->open(hd files, bufio->OREAD)) == nil)
fatal(sys->sprint("can't open '%s'", hd files));
}
else if ((infile = bufio->fopen(sys->fildes(0), bufio->OREAD)) == nil)
fatal("can't buffer stdin");
files = tl files;
return 1;
}
dbg(s: string)
{
if (dflag)
sys->print("dbg: %s\n", s);
}
usage()
{
sys->fprint(stderr(), "usage: %s [-ngd] [-e expr] [-f file] [expr] [file...]\n",
arg->progname());
exits("usage");
}
fatal(s: string)
{
f := filename;
if (f == nil)
f = "<stdin>";
sys->fprint(stderr(), "%s:%d %s\n", f, lnum, s);
exits("error");
}
exits(e: string)
{
for(; bufioflush != nil; bufioflush = tl bufioflush)
(hd bufioflush).flush();
if (e != nil)
raise "fail:" + e;
exit;
}
stderr() : ref Sys->FD
{
return sys->fildes(2);
}