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Bash Script if Statements: Compare Operators

💡 Bash Script if Statements: Compare Operators — Executive Summary

Technical architectural analysis, practical configuration manifests, and deployment instructions for Bash Script if Statements: Compare Operators.

if

Expression	Use	Features	POSIX Compatibility
`if ; then`	Branch based on command execution result	Judging by the exit code after executing the command	fully compatible
`if [ ]; then`	Basic conditional expression evaluation	Use external command test, space strict	POSIX standard
`if [[ ]]; then`	Extended conditional expression evaluation	More flexible and safer, string pattern matching possible	Bash/Zsh only (incompatible)
`if (( }}; then`	Evaluation of arithmetic conditional expressions	Dedicated to arithmetic expressions, optimized for integer operations and comparisons, built-in	Bash/Zsh only (incompatible)

Features

POSIX std

bash

# 빈 조건
if [ -z "$1" ]; then
  echo "비었음"
fi
if [ -n "$1" ]; then
  echo "비어있지 않음"
fi

bash/zsh

bash

# 삼항연산자
BOOL=$( [[ <조건문 삽입> ]] && echo "true" || echo "false" )

# 문자열이 특정 문자열을 포함하는지 확인
if [[ "$ORIGIN" == *"MyString"* ]]; then
  echo "문자열이 포함되어 있습니다."
else
  echo "문자열이 포함되어 있지 않습니다."
fi

# 같음
if [[ "$COMPLETION" -eq 1 ]]; then
fi

ETC

bash

# sudo/root 확인
if [[ $EUID -eq 0 ]]; then
  echo "sudo/root 권한입니다."
fi

Posted:

2026-11-04

Category: Utilities

Author:

fredric

Tags:

Architecture, Bash, CLI, CloudNative, DeepDive, DevOps, English, Guide, Linux, OpenSource, ServerManagement, ServerOps, ShellScript, SysAdmin, SystemEngineering, SystemOps, TechGuide, Tutorial

Bash Script if Statements: Compare Operators

if

Features

POSIX std

bash/zsh

ETC

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