bash-misc-tools

Small Bash utilities for routine infrastructure, certificate, file, and CSV-oriented tasks. The repository is intentionally lightweight and keeps each tool as a standalone script.

Layout

.
├── certificates/
├── data/
├── files/
├── network/
├── CONTRIBUTING.md
└── README.md

Scope

This repository collects miscellaneous shell helpers that were created for practical administrative tasks. Some scripts are generic, while others reflect specific operational environments and should be reviewed before reuse.

Requirements

• Bash
• Standard Unix utilities such as awk, grep, sed, tail, and mv
• ssh-keygen for SSH key inspection
• openssl for certificate inspection and request generation
• nc for TCP connectivity checks
• mail for the legacy certificate request workflow in mkcertreq.sh

Scripts

network/check-connectivity.sh

Checks whether a TCP port is reachable from the current host by using nc.

• Primary use: quick validation of listener reachability without using telnet
• Default port: 50008
• Typical use: ./network/check-connectivity.sh hostname.example 443
• Exit codes: 0 on success, 1 on connection failure, 2 on missing arguments, 127 when nc is unavailable

network/check-ssh-key.sh

Prints three SSH key properties for the supplied public or private key file.

• Output 1: key length
• Output 2: key fingerprint hash token
• Output 3: key type
• Typical use: ./network/check-ssh-key.sh ~/.ssh/id_rsa.pub

certificates/listCertDetails.sh

Reads one or more PEM certificates from a file and prints the subject and issuer for each certificate block.

• Primary use: inspecting certificate bundles or concatenated PEM files
• Input expectation: a text file containing one or more BEGIN CERTIFICATE and END CERTIFICATE blocks
• Typical use: ./certificates/listCertDetails.sh fullchain.pem

certificates/mkcertreq.sh

Generates a private key, certificate signing request, archival tarball, and notification email for a server certificate workflow.

• Primary use: legacy server certificate request preparation
• Environment assumptions: writable /root/certs, local mail command, and OpenSSL installed in standard locations
• Input expectation: one site or hostname argument
• Typical use: ./certificates/mkcertreq.sh site.example

This script is environment-specific and should be reviewed carefully before use in a different organization or host layout.

files/split_with_number_prefix.sh

Renames files that share a common prefix by appending a zero-padded numeric suffix.

• Primary use: renaming outputs after a prior split operation
• Current suffix width: 3
• Typical use: ./files/split_with_number_prefix.sh x

If files such as xaa, xab, and xac exist, the script renames them to x001, x002, and x003.

data/uniquePrograms.sh

Reads a CSV of current courses and appends matching program-course associations from a second file into ProgsWithCourseAssocs.csv.

• Input 1: file containing active program associations
• Input 2: CSV file whose first column contains course identifiers
• Output: ProgsWithCourseAssocs.csv
• Typical use: ./data/uniquePrograms.sh active_programs.txt current_courses.csv

Usage Notes

• Review every script before running it against production systems.
• Run scripts with explicit paths to input files to avoid accidental reads from the wrong directory.
• Prefer testing in a temporary directory when a script modifies files.
• Some scripts predate stricter shell portability and safety conventions; local adaptation may be appropriate.

Organization Notes

Scripts are grouped by function to improve discoverability:

• network/ for connectivity and SSH-related utilities
• certificates/ for certificate inspection and request generation
• files/ for file renaming or split-output helpers
• data/ for CSV or text-processing scripts

Additional category folders can be introduced as needed while preserving this domain-based layout.

Version Control

See CONTRIBUTING.md for the expected branch and merge workflow.