This article explains how to correctly use shell variables and variable substitution in sed, clarifies quoting rules, demonstrates retrieving the last N lines, handling backreferences, the -i option, greedy matching, the interplay of a and N commands, exclamation negation, and troubleshooting high CPU usage.
This guide shares five practical tips to prevent frequent Bash variable errors—such as spacing around the equals sign, array syntax, quoting rules, command substitution, and naming conflicts with environment variables—helping developers write reliable shell scripts.
This article explains how to perform arithmetic with the expr command, assign results to variables, extract information using command substitution, and correctly apply quoting and backticks in Bash to handle spaces, special characters, and nested commands.
This article explains shell command substitution, comparing backticks and the modern $(…) syntax, details their handling of special characters, demonstrates nesting and backslash escaping tricks across various shells, and provides practical examples and solutions for reliable quoting and path handling.
This article explains literal versus meta characters in shells, the three quoting methods (escape, strong, weak), and demonstrates why printing backslashes with echo requires different numbers of backslashes in Bash and Ksh, including work‑arounds like the -E option and set -x debugging.
This article compiles thirteen fundamental Linux shell questions covering the origin of the term "shell", the relationship between PS1 and carriage return, echo command usage, differences between single and double quotes, variable assignment, export behavior, and practical quoting techniques, providing clear explanations and examples for each.
