4 files changed, 57 insertions, 56 deletions

diff --git a/userspace/cat.c b/userspace/cat.c
index 94cbdaa..41768ea 100644
--- a/userspace/cat.c
+++ b/userspace/cat.c
@@ -3,34 +3,39 @@
 
 int main(int argc, char **argv)
 {   
-    printf("hmm\n");
-    printf("pwd=%s\n",getenv("PWD"));
-    FILE *f;
-    if(argc>1){
-	char buf[256];
-	if(argv[1][0]!='/')
-	{
-	    sprintf(buf,"%s/%s",getenv("PWD"),argv[1]);
-	    printf("cat %s\n",buf);
-	    f=fopen(buf,"r");
-	}
-	else
-	{
-	    printf("cat %s\n",argv[1]);
-	    f=fopen(argv[1],"r");
-	}
-    }
-    else f=stdin;
+	// Input (default stdin)
+	FILE *in=stdin;
+
+	// Output
+	FILE *out=stdout;
 
-    setvbuf(stdin,NULL,_IONBF,0);
-    setvbuf(stdout,NULL,_IONBF,0);
+	// In case a Filename was supplied
+	if(argc>1){
+		char buf[256];
 
-    char c;
+		// Relative Path
+		if(argv[1][0]!='/')
+		{
+		    sprintf(buf,"%s/%s",getenv("PWD"),argv[1]);
+		    in=fopen(buf,"r");
+		}
 
-    while(fread(&c,1,1,f))
-    {
-	printf("%c",c);
-    }
+		// Absolute Path
+		else
+		{
+		    in=fopen(argv[1],"r");
+		}
+	}
+
+	char buf[256];
+
+	while(1)
+	{
+		int l=fread(buf,1,255,in);
+		buf[l]=0;
+		if(l==0)break;
+		fwrite(buf,1,l,out);
+	}
 
-    return 0;
+	return EXIT_SUCCESS;
 }
diff --git a/userspace/grep.c b/userspace/grep.c
index c37392f..68d5b7a 100644
--- a/userspace/grep.c
+++ b/userspace/grep.c
@@ -3,15 +3,17 @@
 
 int main(int argc, char **argv)
 {
-    while(1)
-    {
-	char buf[256];
-	int l=fread(buf,1,255,stdin);
-	if(l==0)break;
-	buf[l]=0;
-	printf("grep: %s",buf);
+	FILE *in=stdin;
+	FILE *out=stdout;
 
-    }
+	while(1)
+	{
+	    char buf[2];
+	    int l=fread(buf,1,1,in);
+	    if(l==0)break;
+	    buf[l]=0;
+	    fwrite(buf,1,l,out);
+	}
 
-    return EXIT_SUCCESS;
+	return EXIT_SUCCESS;
 }
diff --git a/userspace/newcalls.h b/userspace/newcalls.h
index 9bc55a5..4568711 100644
--- a/userspace/newcalls.h
+++ b/userspace/newcalls.h
@@ -3,6 +3,7 @@
 // this syscall will be moved to newlib later!
 #define SYSCALL_CLONE 83
 #define SYSCALL_PIPE 84
+#define SYSCALL_DUP2 86
 
 int _clone(void)
 {
@@ -12,4 +13,8 @@ int _pipe(uint32_t fds[2])
 {
     return syscall(SYSCALL_PIPE,fds,0,0);
 }
+int _dup2(uint32_t oldfd,uint32_t newfd)
+{
+    return syscall(SYSCALL_DUP2,oldfd,newfd,0);
+}
 //
diff --git a/userspace/piper.c b/userspace/piper.c
index f45248e..80cbd27 100644
--- a/userspace/piper.c
+++ b/userspace/piper.c
@@ -1,38 +1,27 @@
 #include <stdio.h>
 #include "newcalls.h"
 
+extern **environ;
+
 int main()
 {
     int fds[2];
     _pipe(fds);
 
-    printf("opened pipe / in fd=%d,out fd=%d\n",fds[0],fds[1]);
-
     int pid=_fork();
 
     if(pid)
     {
-	while(1) // read forever from our pipe and echo to stdout
-	{
-	    char buf[256];
-	    int len=fread(buf,1,255,fds[0]);
-	    //int len=_read(fds[0],buf,255);
-	    buf[len]=0;
-	    printf("-\n");
-	    printf("%s\n",buf);
-	    printf("-\n");
-	}
-
+	_close(fds[1]);
+	_dup2(fds[0],0); // replace stdin with the read-end of pipe
+	char *args[]={"grep",NULL};
+	_execve("/bin/grep",args,environ);
     }
     else
     {
-
-	// write to our pipe
-        _write(fds[1],"Hello\n",fds[1]);
-        _write(fds[1],"Bello\n",fds[1]);
-
-	// hang forever
-	while(1);
+	_close(fds[0]);
+	_dup2(fds[1],1); // replace stdout with the write-end of our pipe
+	char *args[]={"cat","hello.txt",0};
+	_execve("/bin/cat",args,environ);
     }
-
 }