diff --git a/lib/cmd.tcl b/lib/cmd.tcl
new file mode 100755
index 0000000..5aa5c0f
--- /dev/null
+++ b/lib/cmd.tcl
@@ -0,0 +1,120 @@
+#!/usr/bin/wish
+
+# This file provides shell command procedures cmd_fnc and t_cmd_fnc.
+
+my_source [list print.tcl]
+
+
+proc cmd_fnc { cmd_buf { quiet {} } { test_mode {} } { print_output {} }\
+  { show_err {} } { ignore_err {} } { acceptable_shell_rcs {} } } {
+
+  # Run the given command in a shell and return the shell return code and the
+  # output as a 2 element list.
+
+  # Example usage:
+  # set result [cmd_fnc "date"].
+
+  # Example output:
+
+  # #(CST) 2018/01/17 16:23:28.951643 -    0.001086 - Issuing: date
+  # Mon Feb 19 10:12:10 CST 2018
+  # result:
+  #   result[0]:                                      0x00000000
+  #   result[1]:                                      Mon Feb 19 10:12:10 CST
+  # 2018
+
+  # Note: Because of the way this procedure processes parms, the user can
+  # specify blank values as a way of skipping parms.  In the following
+  # example, the caller is indicating that they wish to have quiet and
+  # test_mode take their normal defaults but have print_output be 0.:
+  # cmd_fnc "date" "" "" 0
+
+  # Description of argument(s):
+  # cmd_buf                         The command string to be run in a shell.
+  # quiet                           Indicates whether this procedure should
+  #                                 run the print_issuing() procedure which
+  #                                 prints "Issuing: <cmd string>" to stdout.
+  #                                 The default value is 0.
+  # test_mode                       If test_mode is set, this procedure will
+  #                                 not actually run the command.  If
+  #                                 print_output is set, it will print
+  #                                 "(test_mode) Issuing: <cmd string>" to
+  #                                 stdout.  The default value is 0.
+  # print_output                    If this is set, this procedure will print
+  #                                 the stdout/stderr generated by the shell
+  #                                 command.  The default value is 1.
+  # show_err                        If show_err is set, this procedure will
+  #                                 print a standardized error report if the
+  #                                 shell command returns non-zero.  The
+  #                                 default value is 1.
+  # ignore_err                      If ignore_err is set, this procedure will
+  #                                 not fail if the shell command fails.
+  #                                 However, if ignore_err is not set, this
+  #                                 procedure will exit 1 if the shell command
+  #                                 fails.  The default value is 1.
+  # acceptable_shell_rcs            A list of acceptable shell rcs.  If the
+  #                                 shell return code is found in this list,
+  #                                 the shell command is considered
+  #                                 successful.  The default value is {0}.
+
+  # Set defaults.
+  set_var_default quiet [get_stack_var quiet 0 2]
+  set_var_default test_mode 0
+  set_var_default print_output 1
+  set_var_default show_err 1
+  set_var_default ignore_err 1
+  set_var_default acceptable_shell_rcs 0
+
+  qpissuing $cmd_buf $test_mode
+
+  if { $test_mode } { return [list 0 ""] }
+
+  set shell_rc 0
+
+  if { [ catch {set out_buf [eval exec bash -c {$cmd_buf}]} result ] } {
+    set out_buf $result
+    set shell_rc [lindex $::errorCode 2]
+  }
+
+  if { $print_output } { puts "${out_buf}" }
+
+  # Check whether return code is acceptable.
+  if { [lsearch -exact $acceptable_shell_rcs ${shell_rc}] == -1 } {
+    # The command failed.
+    append error_message "The prior shell command failed.\n"
+    append error_message [sprint_var shell_rc "" "" 1]
+    if { $acceptable_shell_rcs != 0 } {
+      # acceptable_shell_rcs contains more than just a single element equal
+      # to 0.
+      append error_message "\n"
+      append error_message [sprint_list acceptable_shell_rcs "" "" 1]
+    }
+    if { ! $print_output } {
+      append error_message "out_buf:\n${out_buf}"
+    }
+    if { $show_err } {
+      print_error_report $error_message
+    }
+
+    if { ! $ignore_err } {
+      exit 1
+    }
+
+  }
+
+  return [list $shell_rc $out_buf]
+
+}
+
+
+proc t_cmd_fnc { args } {
+
+  # Call cmd_fnc with test_mode=1.  See cmd_fnc (above) for details for all
+  # other argument details..
+
+  set_var_default test_mode [get_stack_var test_mode 0 2]
+  set args [lreplace $args 2 2 $test_mode]
+
+  return [cmd_fnc {*}$args]
+
+}