Change _p9strsig to return nil if tmp==nil.

Add atoi, atol, atoll.
These versions call strtol/strtoll with base==0.
The Unix versions use base==10.

src/lib9/atoi.c

diff --git a/src/lib9/atoi.c b/src/lib9/atoi.c
new file mode 100644
index 0000000..66ecb4e
--- /dev/null
+++ b/src/lib9/atoi.c
@@ -0,0 +1,9 @@
+#include <u.h>
+#include <libc.h>
+
+int
+atoi(char *s)
+{
+	return strtol(s, 0, 0);
+}
+

src/lib9/atol.c

diff --git a/src/lib9/atol.c b/src/lib9/atol.c
new file mode 100644
index 0000000..d671383
--- /dev/null
+++ b/src/lib9/atol.c
@@ -0,0 +1,9 @@
+#include <u.h>
+#include <libc.h>
+
+long
+atol(char *s)
+{
+	return strtol(s, 0, 0);
+}
+

src/lib9/atoll.c

diff --git a/src/lib9/atoll.c b/src/lib9/atoll.c
new file mode 100644
index 0000000..6c345df
--- /dev/null
+++ b/src/lib9/atoll.c
@@ -0,0 +1,9 @@
+#include <u.h>
+#include <libc.h>
+
+vlong
+atoll(char *s)
+{
+	return strtoll(s, 0, 0);
+}
+

src/lib9/await.c

diff --git a/src/lib9/await.c b/src/lib9/await.c
index a97c6d1..c6c7122 100644
--- a/src/lib9/await.c
+++ b/src/lib9/await.c
@@ -56,6 +56,8 @@
 	for(i=0; i<nelem(tab); i++)
 		if(tab[i].sig == sig)
 			return tab[i].str;
+	if(tmp == nil)
+		return nil;
 	sprint(tmp, "sys: signal %d", sig);
 	return tmp;
 }

src/lib9/mkfile

diff --git a/src/lib9/mkfile b/src/lib9/mkfile
index 4dda2e1..6dfab74 100644
--- a/src/lib9/mkfile
+++ b/src/lib9/mkfile
@@ -72,6 +72,9 @@
 	announce.$O\
 	argv0.$O\
 	atexit.$O\
+	atoi.$O\
+	atol.$O\
+	atoll.$O\
 	atnotify.$O\
 	await.$O\
 	cistrcmp.$O\