bash.py

#!/usr/bin/env python3

# ----------------------------------------------------------------------------------------------------------------------
import display


def format_alias(alias_name,
                 alias_value):
    """
    Given an alias name and an alias value, returns a bash command to set that alias.

    :param alias_name: The name of the alias.
    :param alias_value: The value of the alias.

    :return: A string representing the bash command that would set this alias.
    """

    return "alias " + alias_name + "='" + alias_value + "'"


# ----------------------------------------------------------------------------------------------------------------------
def format_env(env_name,
               env_value):
    """
    Given an environmental variable name and an environmental variable value, returns a bash command to set that
    environmental variable.

    :param env_name: The name of the environmental variable.
    :param env_value: The value of the environmental variable.

    :return: A string representing the bash command that would set this environmental variable.
    """

    return "export " + env_name + "='" + env_value.replace("'", "\\'") + "'"


# ----------------------------------------------------------------------------------------------------------------------
def format_path_var(path_var_name,
                    path_var_values):
    """
    Given a name of a path environmental variable and a list of paths to set for this variable, returns a bash command
    to set that path variable.

    :param path_var_name: The name of the path variable.
    :param path_var_values: A list of path to set for this path variable.

    :return: A string representing the bash command that would set this path variable.
    """

    output = ":".join(path_var_values)

    return "export " + path_var_name + "='" + output + "'"


# ----------------------------------------------------------------------------------------------------------------------
def unset_env_var(var_name):
    """
    Removes an env var..

    :param var_name: The name of the env var to unset

    :return: Nothing.
    """

    output = "unset " + var_name

    return output


# ----------------------------------------------------------------------------------------------------------------------
def unalias(alias_name):
    """
    Removes an alias..

    :param alias_name: The name of the alias to unset

    :return: Nothing.
    """

    output = "unalias " + alias_name

    return output


# ----------------------------------------------------------------------------------------------------------------------
def export_shell_command(cmds):
    """
    Exports the command for the calling bash shell script to process. Fairly
    simple: It concatenates the list of commands using a semi-colon and then
    simply prints it to stdout.

    :param cmds: A list of shell commands to run.

    :return: Nothing.
    """

    output = ""

    for cmd in cmds:
        if ";" in cmd:
            msg = "This use package has a ; somewhere in one of the commands. This is not allowed."
            display.display_error(msg, quit_after_display=True)
        output += cmd + ";"

    print(output)