2 files changed, 57 insertions, 0 deletions
diff --git a/src/lib9/get9root.c b/src/lib9/get9root.c
new file mode 100644
index 00000000..858b4e74
--- /dev/null
+++ b/src/lib9/get9root.c
@@ -0,0 +1,13 @@
+#include <u.h>
+#include <libc.h>
+
+char*
+get9root(void)
+{
+	char *s;
+
+	if((s = getenv("PLAN9")) != 0)
+		return s;
+	return "/usr/local/plan9";
+}
+
diff --git a/src/lib9/unsharp.c b/src/lib9/unsharp.c
new file mode 100644
index 00000000..b7db700c
--- /dev/null
+++ b/src/lib9/unsharp.c
@@ -0,0 +1,44 @@
+#include <u.h>
+#include <libc.h>
+
+/*
+ * I don't want too many of these,
+ * but the ones we have are just too useful. 
+ */
+static struct {
+	char *old;
+	char *new;
+} replace[] = {
+	"#9", nil,	/* must be first */
+	"#d", "/dev/fd",
+};
+
+char*
+unsharp(char *old)
+{
+	char *new;
+	int i, olen, nlen, len;
+
+	if(replace[0].new == nil)
+		replace[0].new = get9root();
+
+	for(i=0; i<nelem(replace); i++){
+		if(!replace[i].new)
+			continue;
+		olen = strlen(replace[i].old);
+		if(strncmp(old, replace[i].old, olen) != 0
+		|| (old[olen] != '\0' && old[olen] != '/'))
+			continue;
+		nlen = strlen(replace[i].new);
+		len = strlen(old)+nlen-olen;
+		new = malloc(len+1);
+		if(new == nil)
+			/* Most callers won't check the return value... */
+			sysfatal("out of memory translating %s to %s%s", old, replace[i].new, old+olen);
+		strcpy(new, replace[i].new);
+		strcpy(new+nlen, old+olen);
+		assert(strlen(new) == len);
+		return new;
+	}
+	return old;
+}