From 84f719e58391e0810dab663c0f9f9f44d04bd492 Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Fri, 11 May 2001 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 2001-05-11

---
 port/devproc.c | 34 ++++++++++++++++++++++++++++++++++
 port/portdat.h |  3 +++
 port/sysproc.c | 23 ++++++++++++++++++++++-
 3 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/port/devproc.c b/port/devproc.c
index 96b65175683424d1694a7860b17bc390a8701c43..daa8cc56c381f2070ca767fbbf750468c9042496 100644
--- a/port/devproc.c
+++ b/port/devproc.c
@@ -9,6 +9,7 @@
 enum
 {
 	Qctl,
+	Qargs,
 	Qdir,
 	Qfd,
 	Qfpregs,
@@ -30,6 +31,7 @@ enum
 #define	STATSIZE	(2*NAMELEN+12+9*12)
 Dirtab procdir[] =
 {
+	"args",	{Qargs},		0,			0440,
 	"ctl",		{Qctl},		0,			0000,
 	"fd",		{Qfd},		0,			0000,
 	"fpregs",	{Qfpregs},	sizeof(FPsave),		0000,
@@ -233,6 +235,7 @@ procopen(Chan *c, int omode)
 			error(Eperm);
 		break;
 
+	case Qargs:
 	case Qctl:
 	case Qnote:
 	case Qnoteid:
@@ -405,6 +408,28 @@ int2flag(int flag, char *s)
 	*s = '\0';
 }
 
+static int
+procargs(Proc *p, char *buf, int nbuf)
+{
+	int j, k, m;
+	char *a;
+	int n;
+
+	a = p->args;
+	n = p->nargs;	
+	for(j = 0; j < nbuf - 1; j += m){
+		if(n == 0)
+			break;
+		if(j != 0)
+			buf[j++] = ' ';
+		m = snprint(buf+j, nbuf-j, "%q",  a);
+		k = strlen(a) + 1;
+		a += k;
+		n -= k;
+	}
+	return j;
+}
+
 static long
 procread(Chan *c, void *va, long n, vlong off)
 {
@@ -428,6 +453,15 @@ procread(Chan *c, void *va, long n, vlong off)
 		error(Eprocdied);
 
 	switch(QID(c->qid)){
+	case Qargs:
+		j = procargs(p, statbuf, sizeof statbuf);
+		if(offset >= j)
+			return 0;
+		if(offset+n > j)
+			n = j-offset;
+		memmove(a, &statbuf[offset], n);
+		return n;
+
 	case Qmem:
 		if(offset < KZERO
 		|| (offset >= USTKTOP-USTKSIZE && offset < USTKTOP))
diff --git a/port/portdat.h b/port/portdat.h
index 026fa2cf8a2d8ff665bbd25d0454de13b05ae2c0..a6aac9ea967028128f372d96191778c9ad571f15 100644
--- a/port/portdat.h
+++ b/port/portdat.h
@@ -534,6 +534,8 @@ struct Proc
 	Mach	*mach;		/* machine running this proc */
 	char	text[NAMELEN];
 	char	user[NAMELEN];
+	char	*args;
+	int	nargs;		/* number of bytes of args */
 	Proc	*rnext;		/* next process in run queue */
 	Proc	*qnext;		/* next process on queue for a QLock */
 	QLock	*qlock;		/* addrof qlock being queued for DEBUG */
@@ -753,6 +755,7 @@ extern int nsyscall;
 #pragma	varargck	type	"e"	double
 #pragma	varargck	type	"g"	double
 #pragma	varargck	type	"s"	char*
+#pragma	varargck	type	"q"	char*
 #pragma	varargck	type	"S"	Rune*
 #pragma	varargck	type	"r"	void
 #pragma	varargck	type	"%"	void
diff --git a/port/sysproc.c b/port/sysproc.c
index 440e7cfc78648a96a99731e6dff17f960fda2ebe..639c6b9a1fa11d185b54374292b441e0c37886e4 100644
--- a/port/sysproc.c
+++ b/port/sysproc.c
@@ -214,7 +214,7 @@ sysexec(ulong *arg)
 	int i;
 	Chan *tc;
 	char **argv, **argp;
-	char *a, *charp, *file;
+	char *a, *charp, *args, *file;
 	char *progarg[sizeof(Exec)/2+1], elem[NAMELEN];
 	ulong ssize, spage, nargs, nbytes, n, bssend;
 	int indir;
@@ -334,6 +334,7 @@ sysexec(ulong *arg)
 	 */
 	argv = (char**)(TSTKTOP - ssize);
 	charp = (char*)(TSTKTOP - nbytes);
+	args = charp;
 	if(indir)
 		argp = progarg;
 	else
@@ -352,6 +353,26 @@ sysexec(ulong *arg)
 
 	memmove(up->text, elem, NAMELEN);
 
+	/* copy args; easiest from new process's stack */
+	n = charp - args;
+	if(n > 128)	/* don't waste too much space on huge arg lists */
+		n = 128;
+	a = up->args;
+	up->args = nil;
+	free(a);
+	up->args = smalloc(n);
+	memmove(up->args, args, n);
+	if(n>0 && up->args[n-1]!='\0'){
+		/* make sure last arg is NUL-terminated */
+		/* put NUL at UTF-8 character boundary */
+		for(i=n-1; i>0; --i)
+			if(fullrune(up->args+i, n-i))
+				break;
+		up->args[i] = 0;
+		n = i+1;
+	}
+	up->nargs = n;
+
 	/*
 	 * Committed.
 	 * Free old memory.