diff --git a/see_also/exec b/see_also/exec
new file mode 100644
index 0000000..2d3617c
--- /dev/null
+++ b/see_also/exec
@@ -0,0 +1,4 @@
+sh
+bash
+zsh
+exec
diff --git a/sheets/exec b/sheets/exec
new file mode 100644
index 0000000..0e6e030
--- /dev/null
+++ b/sheets/exec
@@ -0,0 +1,17 @@
+# exec
+#
+# Shell builtin command
+# It can start a new process to replace the shell, without a new process creation.
+# It can make redirections take effect in the current shell
+
+# Redirect the output of an entire shell script within the script itself
+# Only stdout:
+exec > foo.log
+
+# Redirect the output of an entire shell script within the script itself
+# Stdout and stderr:
+exec > foo.log 2>&1
+
+# Copy output to a log file
+exec >  >(tee -ia foo.log)
+exec 2> >(tee -ia foo.log >&2)