A printer comprising: a printer unit capable of printing a bar code based on bar code data; an input unit that is configured to allow input operations; a data generator unit that is configured to generate an operation command string from a sequence of input operations by linking together operation commands each corresponding to an input operation through the input unit ; a data recorder unit that is configured to record the operation command string generated by the data generator unit ; and a bar-code-converter unit that is configured to convert the operation command string recorded by the data recorder unit into two-dimensional bar code data; wherein the printer unit is configured to print a bar code based on the two-dimensional bar code data created by the bar-code-converter unit ; and wherein the printer further comprises: a reader unit that is configured to read the operation command string from the bar code printed by the printer unit ; an executor unit that is configured to execute in order the operation commands of the operation command string read by the reader unit ; characterized in that the printer further comprises: a time setting unit that is configured to set an interval of time for executing each of the operation commands; wherein the executor unit is configured to execute each of the operation commands at the interval of time set by the time setting unit . a printer unit capable of printing a bar code based on bar code data; an input unit that is configured to allow input operations; a data generator unit that is configured to generate an operation command string from a sequence of input operations by linking together operation commands each corresponding to an input operation through the input unit ; a data recorder unit that is configured to record the operation command string generated by the data generator unit ; and a bar-code-converter unit that is configured to convert the operation command string recorded by the data recorder unit into two-dimensional bar code data; wherein the printer unit is configured to print a bar code based on the two-dimensional bar code data created by the bar-code-converter unit ; and wherein the printer further comprises: a reader unit that is configured to read the operation command string from the bar code printed by the printer unit ; an executor unit that is configured to execute in order the operation commands of the operation command string read by the reader unit ; characterized in that the printer further comprises: a time setting unit that is configured to set an interval of time for executing each of the operation commands; wherein the executor unit is configured to execute each of the operation commands at the interval of time set by the time setting unit . a reader unit that is configured to read the operation command string from the bar code printed by the printer unit ; an executor unit that is configured to execute in order the operation commands of the operation command string read by the reader unit ; characterized in that the printer further comprises: a time setting unit that is configured to set an interval of time for executing each of the operation commands; wherein the executor unit is configured to execute each of the operation commands at the interval of time set by the time setting unit . a time setting unit that is configured to set an interval of time for executing each of the operation commands; wherein the executor unit is configured to execute each of the operation commands at the interval of time set by the time setting unit . <EOS>