shithub: riscv

--- a/sys/man/4/ptrap

+++ b/sys/man/4/ptrap

@@ -7,10 +7,7 @@

 .B ptrap

 .I port

 [\fB!\fR]\fIregexp\fR

-[

-.I port

-[\fB!\fR]\fIregexp\fR ...

-]

+[ +\fIattr\fR [\fB!\fR]\fIregexp\fR ... ] ...

 .SH DESCRIPTION

 .I Ptrap

 is a program that mounts itself over a

@@ -20,20 +17,20 @@

 and filters incoming messages according to the rules provided on the command line.

.PP

 .I Ptrap

-accepts an arbitrary number of argument pairs; each pair consists of a port name

-.I port

-and a regular expression

-.I regexp

-(see

-.IR regexp (6)).

-Each incoming message that does not match

-.I regexp

-is discarded.

-The

-.I regexp

-can be optionally prefixed by

-.B !

-to indicate logical inversion (i.e. messages matching the regexp are discarded).

+accepts an arbitrary number of filters;

+each filter applies to a port, and may match over both the data and attributes of plumb messages.

+.PP

+A filter is formatted as a port name, a data filter, and a list of attribute filters.

+.PP

+The data filter is a

+.IR regex (6)

+that matches the plumbed data.

+The attribute filter consists of the attribute name prefixed with a '+', followed by a

+.IR regex (6)

+that matches the contents of the attribute.

+Any regex may be prefixed with a '!' in order to negate a match,

+causing all matches for that regex to be discarded.

+All parts of a filter must match in order for a plumb message to be forwarded.

 .SH EXAMPLES

 Start a

 .IR sam (1)

@@ -51,6 +48,15 @@

.EX

 ptrap edit '!^/sys/src/9/'

sam

+.EE

+.PP

+Start an

+.IR acme (1)

+instance instance dedicated to reading plumbed manual pages:

+.IP

+.EX

+ptrap edit '.*' +action '^showdata' +filename '^/man/'

+acme -c1

.EE

 .SH SOURCE

 .B /sys/src/cmd/ptrap.c

--- a/sys/src/cmd/ptrap.c

+++ b/sys/src/cmd/ptrap.c

@@ -8,6 +8,7 @@

 typedef struct IOProc IOProc;

 typedef struct PFilter PFilter;

+typedef struct FAttr FAttr;

 typedef struct PFid PFid;

 struct IOProc {

@@ -27,11 +28,19 @@

};

 Qid rootqid = {.type QTDIR};

+struct FAttr {

+	char *name;

+	Reprog *filt;

+	int invert;

+	FAttr *next;

+};

 struct PFilter {

 	char *name;

 	Reprog *filt;

-	PFilter *next;

 	int invert;

+	FAttr *attr;

+	PFilter *next;

};

 PFilter *filters;

@@ -162,12 +171,32 @@

 static int

+filter(PFilter *f, Plumbmsg *pm)

+{

+	FAttr *a;

+	char *value;

+	if(!(regexec(f->filt, pm->data, nil, 0) ^ f->invert))

+		return 0;

+	for(a = f->attr; a; a = a->next){

+		value = plumblookup(pm->attr, a->name);

+		if(value == nil)

+			return 0;

+		if(!(regexec(a->filt, value, nil, 0) ^ f->attr->invert))

+			return 0;

+	}

+	return 1;

+}

+static int

 filterread(Req *r, PFid *pf)

 	int rc, len, more;

 	char *buf;

 	Plumbmsg *pm;

+	PFilter *f;

+	f = pf->filter;

 	for(;;){

 		if(pf->msg != nil){

 			rc = r->ifcall.count;

@@ -194,7 +223,7 @@

 			len += rc;

 		free(buf);

-		if(regexec(pf->filter->filt, pm->data, nil, 0) ^ pf->filter->invert){

+		if(filter(f, pm)){

 			pf->msg = plumbpack(pm, &pf->msgn);

 			pf->msgp = 0;

@@ -341,7 +370,7 @@

 void

 usage(void)

-	fprint(2, "usage: %s port regex [ port regex ... ]\n", argv0);

+	fprint(2, "usage: %s port regex [ +attr regex ... ] ...\n", argv0);

 	exits("usage");

@@ -349,6 +378,7 @@

 threadmain(int argc, char **argv)

 	PFilter *f;

+	FAttr *fa;

 	char *p;

 	int i;

@@ -357,19 +387,33 @@

 	}ARGEND;

 	if(argc == 0 || argc % 2) usage();

-	for(i = 0; i < argc; i += 2){

+	for(i = 0; i+1 < argc;){

+		p = argv[i];

 		f = emalloc9p(sizeof(PFilter));

-		f->name = strdup(argv[i]);

+		f->name = estrdup9p(p);

 		p = argv[i+1];

-		if(*p == '!'){

+		if(p[0] == '!'){

 			p++;

 			f->invert = 1;

-		f->filt = regcomp(p);

-		if(f->filt == nil)

-			sysfatal("%r");

+		if((f->filt = regcomp(p)) == nil)

+			sysfatal("regcomp: %r");

 		f->next = filters;

 		filters = f;

+		for(i += 2; p = argv[i], i+1 < argc && p[0] == '+'; i += 2){

+			p++;

+			fa = emalloc9p(sizeof(FAttr));

+			fa->name = estrdup9p(p);

+			p = argv[i+1];

+			if(p[0] == '!'){

+				p++;

+				fa->invert = 1;

+			}

+			if((fa->filt = regcomp(p)) == nil)

+				sysfatal("regcomp: %r");

+			fa->next = f->attr;

+			f->attr = fa;

+		}

 	threadpostmountsrv(&ptrapsrv, nil, "/mnt/plumb", MREPL | MCREATE);