added exec

see_also/exec

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+sh
+bash
+zsh
+exec

sheets/exec

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+# 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)