notebook/notes/bash/prompts.md

title	TARGET DECK	FILE TAGS	tags
Prompts	Obsidian::STEM	bash	bash

Overview

According to Robbins a POSIX-compliant shell (like Bash) generally has the primary and secondary prompts denoted with $ and > respectively. Adjust these values using environment variables $PS1 and PS2 respectively.

%%ANKI Basic What symbol is usually used to denote the primary prompt? Back: $$ Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. https://www.gnu.org/software/gawk/manual/gawk.pdf

END%%

%%ANKI Basic What environment variable controls Bash's primary prompt? Back: $$PS1 Reference: Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916.

END%%

%%ANKI Basic What symbol is usually used to denote the secondary prompt? Back: > Reference: Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. https://www.gnu.org/software/gawk/manual/gawk.pdf

END%%

%%ANKI Basic What environment variable controls Bash's secondary prompt? Back: $$PS2 Reference: Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916.

END%%

Paths supplied to commands are typically "sanitized" by prefixing the path name with ./. This is mentioned in a few different places:

• find -execdir performs this prefixing automatically on all found files.
• awk ambiguously interprets a file named e.g. count=1 as variable assignment. Should write $ awk -f program.awk ./count=1.

%%ANKI Basic What methodology is commonly used to "sanitize" paths supplied as command-line arguments? Back: Prefixing the paths with ./. Reference: Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916.

END%%

Bibliography

• Cooper, Mendel. “Advanced Bash-Scripting Guide,” n.d., 916.
• Robbins, Arnold D. “GAWK: Effective AWK Programming,” October 2023. https://www.gnu.org/software/gawk/manual/gawk.pdf