bashANYversionhelp
bash
bash --versionUseful when checking feature support such as associative arrays or newer shell options.
Bash Cheat Sheet
Comprehensive Bash commands, shell syntax, quoting, variables, redirection, pipelines, and day-to-day scripting patterns.
Export
Copy the compact sheet, download it, or print it.
Download
`D` dense toggle · `C` copy all
Invocation and Help
Start Bash, inspect version, and open a clean shell.
bashANYloginstartup
bash
bash -lLoads login startup files such as /etc/profile and ~/.bash_profile depending on system configuration.
bashANYdebugstartup
bash
bash --noprofile --norcUseful for debugging startup configuration problems.
bashANYinvocationcommand
bash
bash -lc 'echo "$SHELL" && pwd'Common in CI, Docker, and automation where you need Bash semantics for one command.
bashANYsyntaxlint
bash
bash -n script.shGood first step before running a script in production or CI.
bashANYtracedebug
bash
bash -x script.shHelps debug variable expansion and flow control problems.
Shell Basics
Basic commands, chaining, and status codes.
bashANYexit-statusbasics
bash
echo $?A zero status means success by convention.
bashANYoperatorssequence
bash
mkdir -p tmp && cd tmp && pwdUse && for fail-fast sequences.
bashANYoperatorsfallback
bash
grep -q needle file.txt || echo 'not found'Use || for error handling or defaults.
bashANYgroupingshell
bash
{ echo start; date; echo end; }Braces keep variable changes in current shell when syntax is valid.
bashANYsubshellgrouping
bash
( cd /tmp && pwd )Directory changes and variables do not leak back to parent shell.
bashANYpipesfilters
bash
ps aux | grep nginx | grep -v grepPipelines are foundational to shell workflows.
bashANYpipefailset
bash
set -o pipefailImportant for reliable scripts; otherwise only final pipeline status is returned.
Redirection
Redirect stdin, stdout, stderr, and combine streams.
bashANYstdoutredirect
bash
echo 'hello' > out.txtUse >> to append instead of overwrite.
bashANYstdoutappend
bash
echo 'hello' >> out.txtUseful for logs and generated reports.
bashANYstderrredirect
bash
grep needle missing.txt 2> errors.logFile descriptor 2 is stderr.
bashANYstderrstdoutfd
bash
command > all.log 2>&1Very common for logs and debugging shell jobs.
bashANYsilencedevnull
bash
command > /dev/null 2>&1Useful in scripts when output is expected but unneeded.
bashANYheredocinput
bash
cat <<'EOF'
line 1
$HOME is not expanded here
EOFQuoted delimiter disables parameter expansion.
bashANYherestringstdin
bash
grep -o '[0-9]\+' <<< 'order-123'Useful for compact one-liners and tests.
bashANYreadfiles
bash
while IFS= read -r line; do echo "$line"; done < input.txtThe IFS= and -r pattern is the standard safe read loop.
More in Bash
Bash Scripting Patterns and Practical Recipes
Production-minded Bash script patterns for files, arguments, parsing, temp files, logging, retries, and common automation tasks.
Bash Builtins, Job Control, and Shell Behavior
Core Bash builtins, shell options, history, aliases, job control, traps, and interactive-shell behavior.
Bash Arrays, Strings, and Text Handling
Indexed and associative arrays, string handling, read/mapfile, and common Bash text-processing patterns.
Bash Conditionals, Loops, and Functions
Bash if/elif/case logic, test expressions, loops, functions, return codes, and robust control-flow patterns.
Bash Variables, Quoting, and Expansion
Bash variables, parameter expansion, quoting rules, command substitution, arithmetic, and shell expansion patterns.
Recommended next
Terraform Troubleshooting and Migration Cheat Sheet
TERRAFORM
Commands and patterns for debugging, upgrades, migration, and state repair in Terraform.
Terraform HCP Remote and CI Cheat Sheet
TERRAFORM
Commands and snippets for HCP Terraform remote runs, CLI auth, automation, and CI-friendly usage.
Terraform Language Patterns Cheat Sheet
TERRAFORM
High-value HCL patterns for variables, locals, outputs, loops, conditionals, dynamic blocks, and data shaping.
Terraform Modules and Providers Cheat Sheet
TERRAFORM
Commands and snippets for modules, providers, version constraints, registry access, and dependency management.
Terraform Workspaces and State Cheat Sheet
TERRAFORM
Manage Terraform CLI workspaces, local and remote state, imports, and state surgery commands.
Terraform CLI Cheat Sheet
TERRAFORM
Core Terraform CLI commands for init, plan, apply, state, output, variables, workspaces, and automation.