nano ~/.bashrc
should be
vim ~/.bashrc
.DEFINITIONS.
The following definitions are used throughout the rest of this document. blank A space or tab. word A sequence of characters considered as a single unit by the shell. Also known as a token. name A word consisting only of alphanumeric characters and underscores, and beginning with an alphabetic character or an underscore. Also referred to as an identifier. metacharacter A character that, when unquoted, separates words. One of the following: | & ; ( ) < > space tab newline control operator A token that performs a control function. It is one of the following symbols: || & && ; ;; ;& ;;& ( ) | |& <newline>
Lists.
A list is a sequence of one or more pipelines separated by one of the operators ;, &, &&, or ||, and optionally terminated by one of ;, &, or <newline>.
ARITHMETIC EVALUATION.
((expression)) - + unary minus and plus * / % multiplication, division, remainder + - addition, subtraction <= >= < > comparison == != equality and inequality && logical AND || logical OR
CONDITIONAL EXPRESSIONS.
[[ expression ]] Return a status of 0 or 1 depending on the evaluation of the conditional expression. -a file, True if file exists. -d file, True if file exists and is a directory. -f file, True if file exists and is a regular file.
PARAMETERS (Positional Parameters & Special Parameters).
A parameter is an entity that stores values.
EXPANSION.
race expansion, tilde expansion, parameter and variable expansion, command substitution, arithmetic expansion, word splitting, and pathname expansion.
JOB CONTROL.
Job control refers to the ability to selectively stop (suspend) the execution of processes and continue (resume) their execution at a later point.
Title: 'The Linux Command Line'
License: creativecommons:
Attribution-NonCommercial-NoDerivs 3.0 Unported 'CC BY-NC-ND 3.0'
Source(s):
linuxcommand:
'The Linux Command Line: Fifth Internet Edition' by William
Shotts.
archive:
'The Linux Command Line Fifth Internet Edition' by William Shotts.
Title: bash Linux manual page.
License: Bash is Copyright (C) 1989-2022 by the Free
Software Foundation, Inc.
Source(s):
man7: bash(1) — Linux manual
page
man7:
Linux manual pages: alphabetic list of all pages.
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