diff --git a/unix_programming_environment/shell_signal_numbers.txt b/unix_programming_environment/shell_signal_numbers.txt
new file mode 100644
index 00000000..19511090
--- /dev/null
+++ b/unix_programming_environment/shell_signal_numbers.txt
@@ -0,0 +1,9 @@
+------------------------- Table 5.4 -------------------------
+              Shell Signal Numbers
+
+0       shell exit (for any reason, including end of file)
+1       hangup
+2       interrupt (DEL key)
+3       quit (ctl-\; causes program to produce core dump)
+9       kill (cannot be caught or ignored)
+15      terminate, default signal generated by kill(1)