--- title: "Shartli Operatorlar — if/elif/else, test shartlari, case" tags: [linux, bash, shell-scripting, conditionals, devops] difficulty: beginner-intermediate author: hacknow lang: uz --- # Shartli Operatorlar !!! info "Bu darsda" - Bash'da `if/elif/else` yozishni o'rganasiz - `[ ]`, `[[ ]]` va `test` orasidagi farqni tushunasiz - Fayl, string va raqam shartlarini (`-f`, `-z`, `-eq` va h.k.) qo'llaysiz - `case` bilan ko'p tanlovli mantiq yozasiz - O'qish vaqti: ~20 daqiqa - Kerakli bilim: o'zgaruvchilar va funksiyalar (4-dars) --- ## 🪝 Tasavvur qiling... Kecha tunda serveringizga SMS keladi: "Disk 95% to'ldi." Siz uxlab yotibsiz. Agar skript o'z-o'zidan "disk 90% dan oshsa — eski loglarni o'chir, menga xabar ber" deb qaror qabul qila olsa edi — bu muammo bo'lmasdi. Xuddi yo'ldagi svetofor kabi: u sizga faqat uchta savolni beradi — "Yashil? Sariq? Qizil?" — va javobga qarab yo'l ko'rsatadi. Bash'dagi `if/elif/else` aynan shu: bir savol, bir yoki bir necha javob, har javob uchun alohida yo'l. Har bir skript — buyruqlar zanjiri emas, **qarorlar daraxti**. Qaysi faylni o'chirish mumkin? Parol to'g'rimi? Disk to'ldimi? Shu savollarsiz skript "ko'r" bo'lib qoladi. --- ## 5.1 If/elif/else ### Umumiy tuzilma ```mermaid flowchart TD Start([Skript boshlandi]) --> C1{shart 1} C1 -- ha --> A1[1-blok bajariladi] C1 -- yo'q --> C2{shart 2 elif} C2 -- ha --> A2[2-blok bajariladi] C2 -- yo'q --> A3[else bloki bajariladi] A1 --> End([fi — tugadi]) A2 --> End A3 --> End ``` !!! tip "Oddiy qilib aytganda" `if` — "agar". `elif` — "aks holda agar". `else` — "qolgan barcha holat". `fi` — bu `if` ning teskari yozilishi, blokni yopadi. **Sintaksis:** ```bash if [ shart ]; then # agar shart rost bo'lsa elif [ boshqa_shart ]; then # agar birinchi yolg'on, ikkinchisi rost bo'lsa else # hech biri rost bo'lmasa fi ``` > [!NOTE] > `[ shart ]` — kvadrat qavslar ichida har tomondan **bo'shliq** bo'lishi shart. `[$x -eq 5]` xato, `[ $x -eq 5 ]` to'g'ri. ### Amaliy misol — asosiy if ```bash #!/bin/bash basic_if_demo() { # Oddiy if local age=25 if [ $age -ge 18 ]; then echo "Kattasiz" fi # If-else local temperature=15 if [ $temperature -gt 20 ]; then echo "Issiq kun" else echo "Sovuq kun" fi # If-elif-else: bir necha holat local score=85 if [ $score -ge 90 ]; then echo "A'lo" elif [ $score -ge 80 ]; then echo "Yaxshi" # score=85 shu yerga tushadi elif [ $score -ge 70 ]; then echo "Qoniqarli" elif [ $score -ge 60 ]; then echo "O'rtacha" else echo "Yomon" fi } basic_if_demo ``` ### Fayl va katalog shartlari ```bash file_tests_demo() { mkdir -p test_dir echo "test content" > test_file.txt chmod 755 test_file.txt local f="test_file.txt" local d="test_dir" local m="missing.txt" # Mavjudlik [ -e "$f" ] && echo "$f mavjud" # -e: fayl yoki katalog mavjud [ -f "$f" ] && echo "$f oddiy fayl" # -f: oddiy fayl (katalog emas) [ -d "$d" ] && echo "$d katalog" # -d: katalog [ -e "$m" ] || echo "$m mavjud emas" # -e yo'q => xabar # Ruxsatlar [ -r "$f" ] && echo "o'qiladi (-r)" # -r: read [ -w "$f" ] && echo "yoziladi (-w)" # -w: write [ -x "$f" ] && echo "bajariladi (-x)" # -x: execute # Hajm va yangilik [ -s "$f" ] && echo "bo'sh emas (-s)" # -s: size > 0 [ "$f" -nt "$d" ] && echo "$f yangi" # -nt: newer than [ "$f" -ot "$d" ] || echo "$f eski emas" # -ot: older than rm -f test_file.txt; rmdir test_dir } ``` ### String validatsiya ```bash string_tests_demo() { # Email validatsiya validate_email() { local email="$1" if [ -z "$email" ]; then # -z: bo'sh string echo "Email bo'sh"; return 1 elif [[ ! "$email" =~ ^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ ]]; then echo "Noto'g'ri email format"; return 1 else echo "To'g'ri email"; return 0 fi } # O'zbekiston telefon raqami validate_phone() { local phone="$1" phone="${phone// /}" # bo'shliqlarni olib tashlash phone="${phone//-/}" # tire olib tashlash phone="${phone//(/}" phone="${phone//)/}" if [ -z "$phone" ]; then echo "Bo'sh raqam"; return 1 elif [[ ${#phone} -lt 9 ]]; then echo "Juda qisqa"; return 1 elif [[ ! "$phone" =~ ^(\+998|998|8)?[0-9]{9}$ ]]; then echo "Noto'g'ri format"; return 1 else echo "To'g'ri raqam"; return 0 fi } # Parol kuchi validate_password() { local password="$1" local errors=0 [ ${#password} -lt 8 ] && { echo "Juda qisqa (min 8)"; ((errors++)); } [[ ! "$password" =~ [A-Z] ]] && { echo "Katta harf yo'q"; ((errors++)); } [[ ! "$password" =~ [a-z] ]] && { echo "Kichik harf yo'q"; ((errors++)); } [[ ! "$password" =~ [0-9] ]] && { echo "Raqam yo'q"; ((errors++)); } [[ ! "$password" =~ [^a-zA-Z0-9] ]] && { echo "Maxsus belgi yo'q"; ((errors++)); } [ $errors -eq 0 ] && echo "Kuchli parol!" || echo "Zaif parol ($errors kamchilik)" } validate_email "user@example.com" validate_email "invalid-email" validate_phone "+998901234567" validate_phone "invalid" validate_password "MyStr0ng!Pass" validate_password "weak" } ``` ### Ichma-ich (nested) if ```bash nested_if_demo() { # Kirish nazorati: autentifikatsiya + avtorizatsiya user_access_control() { local username="$1" password="$2" resource="$3" if [ "$username" == "admin" ] && [ "$password" == "admin123" ]; then echo "Admin: barcha resurslarga ruxsat" return 0 elif [ "$username" == "user1" ] && [ "$password" == "pass123" ]; then echo "User1 kirdi" if [ "$resource" == "read" ]; then echo "O'qish ruxsati bor"; return 0 else echo "Yozish ruxsati yo'q"; return 1 fi elif [ "$username" == "guest" ]; then if [ "$resource" == "read" ]; then echo "Guest: faqat o'qish"; return 0 else echo "Guest: faqat o'qish huquqi bor"; return 1 fi else echo "Noto'g'ri username yoki parol"; return 1 fi } user_access_control "admin" "admin123" "delete" user_access_control "user1" "pass123" "read" user_access_control "user1" "pass123" "write" user_access_control "guest" "" "read" } ``` ### Murakkab shartlar — tizim monitoringi ```bash advanced_conditions_demo() { system_health_check() { local cpu_usage=$(top -bn1 | grep "Cpu(s)" | awk '{print $2}' | sed 's/%us,//') local memory_usage=$(free | awk '/^Mem:/ {printf "%.1f", $3/$2 * 100}') local disk_usage=$(df / | awk 'NR==2 {print $5}' | sed 's/%//') local load_avg=$(uptime | awk -F'load average:' '{print $2}' | awk '{print $1}' | sed 's/,//') local health_score=100 local warnings=() critical_issues=() # CPU tekshiruv if (( $(echo "${cpu_usage:-0} > 90" | bc -l) )); then critical_issues+=("CPU juda yuqori (${cpu_usage}%)") health_score=$((health_score - 30)) elif (( $(echo "${cpu_usage:-0} > 70" | bc -l) )); then warnings+=("CPU yuqori (${cpu_usage}%)") health_score=$((health_score - 15)) fi # RAM tekshiruv if (( $(echo "${memory_usage:-0} > 90" | bc -l) )); then critical_issues+=("RAM juda yuqori (${memory_usage}%)") health_score=$((health_score - 25)) elif (( $(echo "${memory_usage:-0} > 80" | bc -l) )); then warnings+=("RAM yuqori (${memory_usage}%)") health_score=$((health_score - 10)) fi # Disk tekshiruv if [ ${disk_usage:-0} -gt 95 ]; then critical_issues+=("Disk to'la (${disk_usage}%)") health_score=$((health_score - 35)) elif [ ${disk_usage:-0} -gt 85 ]; then warnings+=("Disk to'layapti (${disk_usage}%)") health_score=$((health_score - 20)) fi # Load average tekshiruv (4 yadro uchun) if (( $(echo "${load_avg:-0} > 8" | bc -l) )); then critical_issues+=("Tizim juda yuklangan (load: ${load_avg})") health_score=$((health_score - 20)) elif (( $(echo "${load_avg:-0} > 4" | bc -l) )); then warnings+=("Tizim yuklangan (load: ${load_avg})") health_score=$((health_score - 10)) fi # Natija chiqarish [ ${#critical_issues[@]} -gt 0 ] && printf "KRITIK: %s\n" "${critical_issues[@]}" [ ${#warnings[@]} -gt 0 ] && printf "OGOHLANTIRISH: %s\n" "${warnings[@]}" if [ $health_score -ge 90 ]; then echo "Tizim soglom ($health_score/100)" elif [ $health_score -ge 70 ]; then echo "Tizim qoniqarli ($health_score/100)" elif [ $health_score -ge 50 ]; then echo "Tizim muammoli ($health_score/100)" else echo "Tizim kritik holatda ($health_score/100)" fi } system_health_check } ``` --- ## 💻 O'zingiz sinab ko'ring — if Terminal oching va quyidagini ishga tushiring: ```bash #!/bin/bash # saqlang: check_disk.sh LIMIT=80 USED=$(df / | awk 'NR==2 {print $5}' | tr -d '%') if [ "$USED" -ge "$LIMIT" ]; then echo "OGOHLANTIRISH: disk ${USED}% to'lgan (chegara: ${LIMIT}%)" else echo "Disk yaxshi: ${USED}% ishlatilgan" fi ``` Nima ko'rasiz? Disk 80% dan kam bo'lsa birinchi, ko'p bo'lsa ikkinchi xabar chiqadi. !!! question "Tekshirib ko'ring" `[ $USED -ge $LIMIT ]` o'rniga `[ $USED >= $LIMIT ]` yozsangiz nima bo'ladi?

Javob — bosib oching

`>=` — bu bash `[ ]` da ishlamaydigan operator. Bash `[ ]` da raqamlar uchun faqat `-eq`, `-ne`, `-lt`, `-le`, `-gt`, `-ge` ishlaydi. Natijada skript xato beradi yoki noto'g'ri ishlaydi. `[[ ]]` da ham raqam uchun `-ge` ishlatiladi, `>=` faqat arifmetik `(( ))` ichida ishlaydi.

--- ## 5.2 Test shartlari — `[ ]`, `[[ ]]`, `test` ### Uchta usul, bir maqsad !!! tip "Oddiy qilib aytganda" `test x -eq 5`, `[ x -eq 5 ]`, `[[ x -eq 5 ]]` — uchalasi ham "x 5 ga tengmi?" deb so'raydi. Farqi imkoniyatlarda. ```mermaid flowchart LR A["test ..."] -- "POSIX (barcha Unix tizimlarida ishlaydigan standart), eng eski" --> D[Natija: 0=rost, 1=yolg'on] B["[ ... ]"] -- "test ning muqobili, portable" --> D C["[[ ... ]]"] -- "Bash kengaytmasi, kuchliroq" --> D ``` ### Sintaksis farqlari — jadval ```bash test_syntax_demo() { local num=42 local str="hello" local file="test.txt" echo "test content" > "$file" # Uch usul ham bir xil natija beradi test $num -eq 42 && echo "test: 42 = 42" [ $num -eq 42 ] && echo "[ ]: 42 = 42" [[ $num -eq 42 ]] && echo "[[ ]]: 42 = 42" # [ ] da string uchun qo'shtirnoq MAJBURIY [ "$str" = "hello" ] && echo "[ ] string: to'g'ri" # [[ ]] da qo'shtirnoqsiz ham ishlaydi, lekin yaxshi amaliyot — doim qo'shtirnoq [[ $str == "hello" ]] && echo "[[ ]] string: to'g'ri" # [[ ]] UCHUN QO'SHIMCHA IMKONIYATLAR: [[ $str == h* ]] && echo "Pattern matching: h bilan boshlanadi" [[ $str =~ ^h.* ]] && echo "Regex: ^h.* ga mos" rm -f "$file" } ``` > [!WARNING] > `[ ]` da o'zgaruvchi qiymati bo'sh bo'lsa (`local x=""`), qo'shtirnoqsiz `[ $x -eq 5 ]` xato beradi — bash uni `[ -eq 5 ]` deb o'qiydi. Doim `"$x"` yozing. ### Fayl test operatorlari — to'liq jadval | Operator | Ma'nosi | Misol | |----------|---------|-------| | `-e` | mavjud (fayl yoki katalog) | `[ -e /etc/passwd ]` | | `-f` | oddiy fayl | `[ -f script.sh ]` | | `-d` | katalog | `[ -d /home ]` | | `-L` | simvolik havola | `[ -L /usr/bin/python ]` | | `-p` | named pipe (nomlangan quvur — jarayonlar orasidagi ma'lumot kanali) | `[ -p /tmp/mypipe ]` | | `-r` | o'qish ruxsati bor | `[ -r config.yml ]` | | `-w` | yozish ruxsati bor | `[ -w /var/log/app.log ]` | | `-x` | bajarish ruxsati bor | `[ -x deploy.sh ]` | | `-s` | hajmi > 0 | `[ -s data.csv ]` | | `-nt` | yangi (newer than) | `[ a.txt -nt b.txt ]` | | `-ot` | eski (older than) | `[ a.txt -ot b.txt ]` | | `-ef` | bir xil fayl (hard link) | `[ a -ef b ]` | !!! tip "Oddiy qilib aytganda" `-f`, `-d`, `-e` — eng ko'p ishlatiladigan uchlik. Skriptda faylga murojaat qilishdan avval doim `-f` bilan tekshiring: "bu fayl mavjudmi?" ### String test operatorlari | Operator | Ma'nosi | Misol | |----------|---------|-------| | `-z` | bo'sh string | `[ -z "$var" ]` | | `-n` | bo'sh emas | `[ -n "$var" ]` | | `=` yoki `==` | teng | `[ "$a" = "$b" ]` | | `!=` | teng emas | `[ "$a" != "$b" ]` | | `<` | alfavit bo'yicha kichik | `[[ "$a" < "$b" ]]` | | `>` | alfavit bo'yicha katta | `[[ "$a" > "$b" ]]` | | `=~` | regex mos keladi | `[[ "$str" =~ ^[0-9]+$ ]]` | !!! question "Tekshirib ko'ring" `[ -z "$var" ]` va `[ "$var" = "" ]` — bu ikkalasi bir xil natija beradimi? Qaysi birini afzal ko'rasiz va nega?

Javob — bosib oching

Ha, ikkalasi ham bir xil natija beradi: o'zgaruvchi bo'sh bo'lsa `true`. Lekin `-z` afzalroq — ixchamroq, o'qilishi osonroq, va qo'shtirnoq unutilsa ham xavfsizroq ishlaydi.

### Raqam test operatorlari | Operator | Ma'nosi | Misol | |----------|---------|-------| | `-eq` | teng | `[ $a -eq $b ]` | | `-ne` | teng emas | `[ $a -ne $b ]` | | `-lt` | kichik | `[ $a -lt $b ]` | | `-le` | kichik yoki teng | `[ $a -le $b ]` | | `-gt` | katta | `[ $a -gt $b ]` | | `-ge` | katta yoki teng | `[ $a -ge $b ]` | ### Mantiqiy operatorlar ```bash # VA (AND) [ $a -gt 0 ] && [ $a -lt 100 ] # ikkita [ ] [[ $a -gt 0 && $a -lt 100 ]] # bitta [[ ]] ichida # YOKI (OR) [ -f "$f" ] || [ -d "$f" ] # ikkita [ ] [[ -f "$f" || -d "$f" ]] # bitta [[ ]] ichida # INKOR (NOT) [ ! -f "$f" ] # fayl EMAS [[ ! -d "$f" ]] # katalog EMAS ``` ### To'liq fayl testlari — amaliy namuna ```bash comprehensive_file_tests() { mkdir -p test_env && cd test_env echo "regular file content" > regular_file.txt mkdir directory touch empty_file ln -s regular_file.txt symbolic_link mkfifo named_pipe 2>/dev/null printf '#!/bin/bash\necho "executable"' > script.sh chmod +x script.sh echo "read only content" > readonly_file.txt chmod 444 readonly_file.txt local files=("regular_file.txt" "directory" "empty_file" "symbolic_link" "named_pipe" "script.sh" "readonly_file.txt" "nonexistent_file") for item in "${files[@]}"; do echo "--- $item ---" [ -e "$item" ] || { echo " mavjud emas"; continue; } [ -f "$item" ] && echo " oddiy fayl (-f)" [ -d "$item" ] && echo " katalog (-d)" [ -L "$item" ] && echo " simvolik havola (-L)" [ -p "$item" ] && echo " named pipe (-p)" [ -r "$item" ] && echo " o'qiladi (-r)" || echo " o'qilmaydi (-r)" [ -w "$item" ] && echo " yoziladi (-w)" || echo " yozilmaydi (-w)" [ -x "$item" ] && echo " bajariladi (-x)" [ -s "$item" ] && echo " bo'sh emas (-s): $(wc -c < "$item" 2>/dev/null) bayt" \ || echo " bo'sh (-s)" done # Fayl taqqoslash echo "content1" > file1.txt; sleep 1; echo "content2" > file2.txt [ file2.txt -nt file1.txt ] && echo "file2 yangi" cp file1.txt file1_copy.txt [ file1.txt -ef file1_copy.txt ] && echo "hard link emas (nusxa)" \ || echo "har xil inode" cd ..; rm -rf test_env } ``` ### Murakkab string testlari ```bash advanced_string_tests() { local email="user@example.com" local phone="+998901234567" local ip="192.168.1.1" local date_str="2024-06-24" local password="MyPassword123!" # Email [[ "$email" =~ ^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ ]] \ && echo "Email to'g'ri" || echo "Email noto'g'ri" # O'zbekiston telefon [[ "$phone" =~ ^\+998[0-9]{9}$ ]] \ && echo "Telefon to'g'ri" || echo "Telefon noto'g'ri" # IP address (format + diapazon) if [[ "$ip" =~ ^([0-9]{1,3}\.){3}[0-9]{1,3}$ ]]; then IFS='.' read -ra ADDR <<< "$ip" local valid=true for octet in "${ADDR[@]}"; do [ "$octet" -gt 255 ] && valid=false done [ "$valid" = true ] && echo "IP to'g'ri" || echo "IP diapazondan tashqari" else echo "IP format noto'g'ri" fi # ISO sana: YYYY-MM-DD if [[ "$date_str" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]]; then local year="${date_str%-*-*}" local month="${date_str#*-}"; month="${month%-*}" local day="${date_str##*-}" [ "$year" -ge 1900 ] && [ "$year" -le 2100 ] \ && [ "$month" -ge 1 ] && [ "$month" -le 12 ] \ && [ "$day" -ge 1 ] && [ "$day" -le 31 ] \ && echo "Sana to'g'ri" || echo "Sana qiymatlari noto'g'ri" fi # Parol kuchi balli local score=0 [[ ${#password} -ge 8 ]] && ((score++)) [[ "$password" =~ [A-Z] ]] && ((score++)) [[ "$password" =~ [a-z] ]] && ((score++)) [[ "$password" =~ [0-9] ]] && ((score++)) [[ "$password" =~ [^a-zA-Z0-9] ]] && ((score++)) echo "Parol kuchi: $score/5" } ``` ### Raqamli diapazon va muhit testlari ```bash numeric_range_tests() { # Yosh kategoriyasi categorize_age() { local age="$1" [[ ! "$age" =~ ^[0-9]+$ ]] && { echo "Noto'g'ri format"; return 1; } if [ "$age" -le 2 ]; then echo "Chaqaloq (0-2)" elif [ "$age" -le 5 ]; then echo "Kichik bola (3-5)" elif [ "$age" -le 12 ]; then echo "Bola (6-12)" elif [ "$age" -le 17 ]; then echo "O'smir (13-17)" elif [ "$age" -le 25 ]; then echo "Yosh katta (18-25)" elif [ "$age" -le 40 ]; then echo "Katta (26-40)" elif [ "$age" -le 60 ]; then echo "O'rta yosh (41-60)" elif [ "$age" -le 80 ]; then echo "Keksa (61-80)" else echo "Juda keksa (80+)" fi } # Harorat kategoriyasi categorize_temperature() { local temp="$1" [[ ! "$temp" =~ ^-?[0-9]+$ ]] && { echo "Noto'g'ri format"; return 1; } if [ "$temp" -le -30 ]; then echo "Ekstremal sovuq" elif [ "$temp" -le -10 ]; then echo "Juda sovuq" elif [ "$temp" -le 0 ]; then echo "Sovuq" elif [ "$temp" -le 10 ]; then echo "Salqin" elif [ "$temp" -le 20 ]; then echo "Iliq" elif [ "$temp" -le 30 ]; then echo "Issiq" elif [ "$temp" -le 40 ]; then echo "Juda issiq" else echo "Ekstremal issiq" fi } # GPA konvertatsiya grade_to_gpa() { local grade="$1" [[ ! "$grade" =~ ^[0-9]+$ ]] || [ "$grade" -gt 100 ] \ && { echo "0-100 oraligida bo'lishi kerak"; return 1; } if [ "$grade" -ge 97 ]; then echo "A+ (4.0)" elif [ "$grade" -ge 93 ]; then echo "A (4.0)" elif [ "$grade" -ge 90 ]; then echo "A- (3.7)" elif [ "$grade" -ge 87 ]; then echo "B+ (3.3)" elif [ "$grade" -ge 83 ]; then echo "B (3.0)" elif [ "$grade" -ge 80 ]; then echo "B- (2.7)" elif [ "$grade" -ge 77 ]; then echo "C+ (2.3)" elif [ "$grade" -ge 73 ]; then echo "C (2.0)" elif [ "$grade" -ge 70 ]; then echo "C- (1.7)" elif [ "$grade" -ge 67 ]; then echo "D+ (1.3)" elif [ "$grade" -ge 65 ]; then echo "D (1.0)" else echo "F (0.0)" fi } for age in 5 13 18 25 45 70 85; do categorize_age "$age"; done for tmp in -25 -5 5 15 25 35 45; do categorize_temperature "$tmp"; done for g in 65 75 85 90 95 100; do grade_to_gpa "$g"; done } environment_tests() { # OS turi if [[ "$OSTYPE" == "linux-gnu"* ]]; then echo "Linux tizim" [ -f /etc/os-release ] && { source /etc/os-release; echo " Distro: $NAME $VERSION"; } [ -f /.dockerenv ] && echo " Docker container ichida" \ || echo " Native Linux" elif [[ "$OSTYPE" == "darwin"* ]]; then echo "macOS" elif [[ "$OSTYPE" == "cygwin" ]]; then echo "Cygwin (Windows)" elif [[ "$OSTYPE" == "msys" ]]; then echo "MSYS (Windows)" else echo "Noma'lum: $OSTYPE" fi # Bash versiyasi if [ -n "$BASH_VERSION" ]; then echo "Bash: $BASH_VERSION" local major="${BASH_VERSION%%.*}" [ "$major" -ge 4 ] && echo " Zamonaviy (4.0+)" || echo " Eski, ba'zi xususiyatlar cheklangan" fi # Foydalanuvchi ruxsatlari if [ "$EUID" -eq 0 ]; then echo "Root foydalanuvchi" else echo "Oddiy foydalanuvchi (UID: $EUID)" sudo -n true 2>/dev/null && echo " Sudo ruxsati bor" || echo " Sudo yo'q" fi # Disk holati local used_pct=$(df -h . 2>/dev/null | awk 'NR==2 {print $5}' | tr -d '%') [ "$used_pct" -gt 90 ] && echo "Disk deyarli to'la!" \ || [ "$used_pct" -gt 80 ] && echo "Disk to'layapti" \ || echo "Disk yaxshi ($used_pct% ishlatilgan)" } ``` --- ## 💻 O'zingiz sinab ko'ring — test shartlari ```bash # saqlang: file_check.sh FILE="$1" if [ -z "$FILE" ]; then echo "Foydalanish: $0 " exit 1 fi if [ -f "$FILE" ]; then echo "$FILE — oddiy fayl" [ -r "$FILE" ] && echo " o'qiladi" [ -w "$FILE" ] && echo " yoziladi" [ -x "$FILE" ] && echo " bajariladi" [ -s "$FILE" ] && echo " hajm: $(wc -c < "$FILE") bayt" || echo " bo'sh" elif [ -d "$FILE" ]; then echo "$FILE — katalog" else echo "$FILE — mavjud emas" fi ``` Ishga tushirish: `bash file_check.sh /etc/passwd` !!! question "Tekshirib ko'ring" `[ ]` va `[[ ]]` orasidagi qaysi ikkita farqni eng muhim deb bilasiz?

Javob — bosib oching

1. **Regex**: `[[ "$str" =~ pattern ]]` — faqat `[[ ]]` da ishlaydi. `[ ]` da regex yo'q. 2. **Xavfsizlik**: `[ ]` da bo'sh o'zgaruvchi (`[ $x -eq 5 ]`) xato berishi mumkin. `[[ ]]` da bu muammo yo'q — o'zgaruvchi qo'shtirnoqsiz ham xavfsiz. Qo'shimcha: `[[ ]]` da `&&` va `||` ishlaydi, `[ ]` da ular tashqarida yoziladi.

!!! warning "Tez-tez uchraydigan xato" `[ ]` ichida `&&` va `||` ishlamaydi: `[ $a -gt 0 && $a -lt 10 ]` — xato. To'g'ri yozuv: `[ $a -gt 0 ] && [ $a -lt 10 ]` yoki `[[ $a -gt 0 && $a -lt 10 ]]`. --- ## 5.3 Case statements ### Svetofor o'rniga yo'l ayirig'i Tasavvur qiling: siz shahar markaziga kirayapsiz. Yo'l to'rtta yo'nalishga ajraladi — har birida belgi bor: "Airport", "Bozor", "Kasalxona", "Stadion". Siz bir marta yo'lni o'qiysiz va to'g'ri tomonga burilasiz. `case` aynan shu: bitta o'zgaruvchini bir marta o'qib, ko'p variant ichidan to'g'risini topadi. Uzoq `if/elif/elif/elif` zanjiri o'rniga — toza, o'qiladigan kod. !!! tip "Oddiy qilib aytganda" `if/elif` — har safar yangi savol beradi. `case` — bir savolni bir marta beradi, javobga qarab yo'l ko'rsatadi. Tezroq, aniqroq. ### case qanday tarmoqlanadi ```mermaid flowchart TD Start([case o'zgaruvchisi]) --> M{qiymatni solishtir} M -- "pattern1 mos" --> B1[1-blok bajariladi] M -- "pattern2 yoki pattern3 mos" --> B2[2-blok bajariladi] M -- "*.txt wildcard mos" --> B3[3-blok bajariladi] M -- "hech biri mos kelmadi" --> B4[default blok - mos] B1 --> End([esac — tugadi]) B2 --> End B3 --> End B4 --> End ``` > [!NOTE] > `case` birinchi mos kelgan patternda to'xtaydi. Qolgan patternlar tekshirilmaydi. Shuning uchun aniqroq patternlar yuqorida tursin. ### Sintaksis ```bash case $variable in pattern1) # pattern1 mos kelganda ;; # bu "break" o'rnida — case blokini yopadi pattern2|pattern3) # pattern2 YOKI pattern3 mos kelganda (| = yoki) ;; *.txt) # wildcard (joker belgi — * istalgan belgilar ketma-ketligi): .txt bilan tugasa ;; *) # hech biri mos kelmasa (default) ;; esac ``` > [!NOTE] > `;;` — har case blokining oxiri. Bash'da C/Java'dagi `break` yo'q — `;;` uni bajaradi. Undan keyin `esac` (bu "case" ning teskari yozilishi) blokni yopadi. ### Asosiy misol — menyu ```bash basic_case_demo() { echo "1. Fayllar ro'yxati" echo "2. Disk maydoni" echo "3. Tizim ma'lumotlari" echo "4. Chiqish" read -p "Tanlov (1-4): " choice case $choice in 1) echo "Fayllar:" ls -la | head -10 ;; 2) echo "Disk:" df -h | head -5 ;; 3) echo "Tizim:" echo "OS: $(uname -o)" echo "Kernel: $(uname -r)" echo "Uptime: $(uptime -p)" ;; 4) echo "Xayr!" ;; *) echo "Noto'g'ri tanlov: $choice (1-4 kiriting)" ;; esac } ``` ### Pattern matching — fayl turi aniqlash ```bash pattern_matching_demo() { detect_file_type() { local filename="$1" case "$filename" in *.txt|*.text) echo "Matn fayli" ;; *.pdf) echo "PDF hujjat" ;; *.doc|*.docx) echo "Word hujjat" ;; *.jpg|*.jpeg|*.png|*.gif|*.bmp) echo "Rasm fayli" ;; *.mp3|*.wav|*.flac|*.aac) echo "Audio fayl" ;; *.mp4|*.avi|*.mkv|*.mov) echo "Video fayl" ;; *.zip|*.rar|*.tar|*.gz|*.7z) echo "Arxiv fayli" ;; *.sh|*.bash) echo "Shell script" ;; *.py) echo "Python script" ;; *.js) echo "JavaScript" ;; *.html|*.htm) echo "HTML fayl" ;; *.css) echo "CSS fayl" ;; .*) echo "Yashirin fayl" ;; */) echo "Katalog" ;; *) echo "Noma'lum tur" ;; esac } local test_files=("document.txt" "photo.jpg" "music.mp3" "archive.zip" "script.sh" "program.py" "webpage.html" ".hidden_file" "folder/" "unknown_file") for f in "${test_files[@]}"; do printf "%-20s -> %s\n" "$f" "$(detect_file_type "$f")" done } ``` ### Command line argumentlarni qayta ishlash ```bash argument_processing_demo() { process_arguments() { local verbose=false output_file="" operation="" local input_files=() while [[ $# -gt 0 ]]; do case $1 in -v|--verbose) verbose=true shift ;; -o|--output) if [[ -n $2 && $2 != -* ]]; then output_file="$2"; shift 2 else echo "Xato: --output uchun fayl nomi kerak"; return 1 fi ;; -f|--file) if [[ -n $2 && $2 != -* ]]; then input_files+=("$2"); shift 2 else echo "Xato: --file uchun fayl nomi kerak"; return 1 fi ;; --operation=*) operation="${1#*=}" # = dan keyingi qismni olish shift ;; -h|--help) cat <&2 ;; FATAL|fatal) echo -e "\033[35m[$ts][FATAL][$caller] $message\033[0m" >&2 echo -e "\033[35m[$ts][FATAL] Ilova to'xtatilmoqda...\033[0m" >&2 ;; *) echo -e "\033[37m[$ts][UNKNOWN][$caller] $message\033[0m" ;; esac } # Debug o'chirilgan holda echo "=== DEBUG=false ===" DEBUG=false process_log "INFO" "Ilova ishga tushdi" process_log "DEBUG" "Bu ko'rinmaydi" process_log "WARN" "Database ulanish sekin (2.5s)" process_log "ERROR" "Query muvaffaqiyatsiz: timeout" process_log "FATAL" "Out of memory" echo echo "=== DEBUG=true ===" DEBUG=true process_log "INFO" "Ilova ishga tushdi" process_log "DEBUG" "Bu endi ko'rinadi" } ``` ### Konfiguratsiya validatori ```bash config_validator_demo() { validate_config() { local config_type="$1" config_value="$2" case "$config_type" in "port") case "$config_value" in [1-9][0-9][0-9][0-9]|[1-5][0-9][0-9][0-9][0-9]|\ 6[0-4][0-9][0-9][0-9]|65[0-4][0-9][0-9]|655[0-2][0-9]|6553[0-5]) [ "$config_value" -lt 1024 ] \ && echo "Privileged port ($config_value): root kerak" \ || echo "Port to'g'ri: $config_value" ;; *) echo "Noto'g'ri port: $config_value (1-65535)"; return 1 ;; esac ;; "log_level") case "$config_value" in DEBUG|INFO|WARN|ERROR|FATAL|\ debug|info|warn|error|fatal) echo "Log level to'g'ri: $config_value" ;; *) echo "Noto'g'ri log level: $config_value"; return 1 ;; esac ;; "database_url") case "$config_value" in postgresql://*|postgres://*) echo "PostgreSQL URL" ;; mysql://*|mysql+pymysql://*) echo "MySQL URL" ;; sqlite:///*|sqlite:///*) echo "SQLite URL" ;; mongodb://*|mongodb+srv://*) echo "MongoDB URL" ;; redis://*|rediss://*) echo "Redis URL" ;; *) echo "Noma'lum DB URL: $config_value"; return 1 ;; esac ;; "memory_limit") case "$config_value" in *[Gg]) local gb="${config_value%[Gg]}" [[ "$gb" =~ ^[0-9]+$ ]] && [ "$gb" -le 64 ] \ && echo "Memory: ${gb}GB" \ || { echo "Juda katta (max 64G)"; return 1; } ;; *[Mm]) local mb="${config_value%[Mm]}" [[ "$mb" =~ ^[0-9]+$ ]] && [ "$mb" -ge 64 ] \ && echo "Memory: ${mb}MB" \ || { echo "Juda kichik (min 64M)"; return 1; } ;; *) echo "Noto'g'ri format: $config_value (512M, 2G)"; return 1 ;; esac ;; "environment") case "$config_value" in development|dev) echo "Development: debug rejim, test ma'lumotlari" ;; staging|stage) echo "Staging: production-like, test environment" ;; production|prod) echo "Production: live, real ma'lumotlar" ;; testing|test) echo "Testing: avtomatik testlar uchun" ;; *) echo "Noma'lum muhit: $config_value (development/staging/production/testing)" return 1 ;; esac ;; "ssl_mode") case "$config_value" in required|require) echo "SSL majburiy — barcha ulanishlar shifrlangan" ;; preferred|prefer) echo "SSL ixtiyoriy — bor bo'lsa ishlatiladi" ;; disabled|disable|none) echo "OGOHLANTIRISH: SSL o'chirilgan (production da tavsiya etilmaydi)" ;; *) echo "Noto'g'ri SSL rejim: $config_value (required/preferred/disabled)" return 1 ;; esac ;; *) echo "Noma'lum konfig turi: $config_type" echo "Qo'llab-quvvatlanadi: port, log_level, database_url, memory_limit, environment, ssl_mode" return 1 ;; esac return 0 } local passed=0 failed=0 local tests=( "port:8080" "port:443" "port:99999" "log_level:INFO" "log_level:INVALID" "database_url:postgresql://user:pass@localhost:5432/db" "database_url:invalid://test" "memory_limit:2G" "memory_limit:512M" "memory_limit:100TB" "environment:production" "environment:invalid_env" "ssl_mode:required" "ssl_mode:invalid_mode" ) for cfg in "${tests[@]}"; do IFS=':' read -r ctype cval <<< "$cfg" validate_config "$ctype" "$cval" && ((passed++)) || ((failed++)) done echo "Natija: $passed muvaffaqiyatli, $failed muvaffaqiyatsiz" } ``` ### Interaktiv konfiguratsiya wizard ```bash config_wizard_demo() { configuration_wizard() { echo "Konfiguratsiya Wizard" echo # Ilova turi local app_type while true; do echo "Ilova turi: 1) Web 2) API 3) Database 4) Microservice" read -p "Tanlov (1-4): " choice case $choice in 1) app_type="web"; break ;; 2) app_type="api"; break ;; 3) app_type="database"; break ;; 4) app_type="microservice"; break ;; *) echo "1-4 oraligida kiriting" ;; esac done # Muhit local env while true; do echo "Muhit: 1) Development 2) Staging 3) Production" read -p "Tanlov (1-3): " choice case $choice in 1) env="development"; break ;; 2) env="staging"; break ;; 3) env="production"; break ;; *) echo "1-3 oraligida kiriting" ;; esac done # Tavsiya etilgan konfiguratsiya echo echo "=== Tavsiya etilgan konfiguratsiya ===" case "$app_type" in "web") case "$env" in "development") echo "PORT=3000" echo "LOG_LEVEL=DEBUG" echo "DATABASE_URL=sqlite:///dev.db" echo "SSL_MODE=disabled" echo "MEMORY_LIMIT=512M" ;; "staging") echo "PORT=8080" echo "LOG_LEVEL=INFO" echo "DATABASE_URL=postgresql://app:pass@staging-db:5432/app_staging" echo "SSL_MODE=preferred" echo "MEMORY_LIMIT=1G" ;; "production") echo "PORT=80" echo "LOG_LEVEL=WARN" echo "DATABASE_URL=postgresql://app:\${DB_PASSWORD}@prod-db:5432/app_prod" echo "SSL_MODE=required" echo "MEMORY_LIMIT=2G" ;; esac ;; "api") case "$env" in "development") echo "API_PORT=5000" echo "LOG_LEVEL=DEBUG" echo "RATE_LIMIT=1000" echo "AUTH_REQUIRED=false" ;; "staging"|"production") echo "API_PORT=443" echo "LOG_LEVEL=INFO" echo "RATE_LIMIT=100" echo "AUTH_REQUIRED=true" echo "SSL_CERT=/etc/ssl/api.crt" ;; esac ;; "database") case "$env" in "development") echo "DB_PORT=5432" echo "MAX_CONNECTIONS=20" echo "BACKUP_ENABLED=false" ;; "staging"|"production") echo "DB_PORT=5432" echo "MAX_CONNECTIONS=100" echo "BACKUP_ENABLED=true" echo "BACKUP_SCHEDULE=0 2 * * *" ;; esac ;; "microservice") echo "SERVICE_PORT=8080" echo "LOG_LEVEL=INFO" echo "METRICS_ENABLED=true" echo "HEALTH_CHECK_PATH=/health" ;; esac echo echo "Tip: Yuqoridagi qiymatlarni .env fayliga saqlang" } configuration_wizard } # Barcha funksiyalarni test qilish (faqat to'g'ridan-to'g'ri ishga tushirilsa) if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then basic_case_demo pattern_matching_demo argument_processing_demo service_controller_demo log_processor_demo config_validator_demo # config_wizard_demo # Interaktiv — qo'lda ishga tushiring fi ``` --- ## 💻 O'zingiz sinab ko'ring — case ```bash #!/bin/bash # saqlang: file_router.sh FILE="$1" [ -z "$FILE" ] && { echo "Foydalanish: $0 "; exit 1; } case "$FILE" in *.sh|*.bash) echo "Shell script — bash $FILE bilan ishga tushiring" ;; *.py) echo "Python script — python3 $FILE bilan ishga tushiring" ;; *.txt) echo "Matn fayli — cat $FILE bilan o'qing" ;; *.gz|*.zip) echo "Arxiv — tar/unzip bilan oching" ;; *) echo "Noma'lum: $FILE" ;; esac ``` Bir nechta faylga sinab ko'ring: `bash file_router.sh script.sh`, `bash file_router.sh data.txt`. !!! question "Tekshirib ko'ring" Quyidagini ishga tushirsangiz nima bo'ladi? ```bash x="hello" case "$x" in h*) echo "h bilan boshlanadi" ;; hello) echo "aynan hello" ;; esac ```

Javob — bosib oching

Faqat birinchi mos kelgan pattern ishlaydi: `h*` `"hello"` ga mos keladi (chunki u `h` bilan boshlanadi), shuning uchun "h bilan boshlanadi" chiqadi. Ikkinchi pattern (`hello`) hech qachon bajarilmaydi — `case` birinchi moslikda to'xtaydi. Shuning uchun pattern tartibiga e'tibor bering: aniqroq patternlar oldinda tursin.

!!! warning "Tez-tez uchraydigan xato" `case` da `;;` unutilsa, bash **keyingi patternni ham bajaradi** (fall-through). Har `case` blokini `;;` bilan yoping. Istisno — ataylab fall-through kerak bo'lsa (kam uchraydi) `;&` ishlatiladi. --- ## 🎒 Xulosa — eng muhimi Agar bu darsdan beshtasini eslab qolsangiz: 1. **`if [ shart ]; then ... fi`** — asosiy tuzilma. `elif` va `else` ixtiyoriy. `fi` yopishni unutmang. 2. **`[ ]` vs `[[ ]]`**: oddiy shartlar uchun ikkalasi ham ishlaydi, lekin `[[ ]]` kuchliroq — regex (`=~`), pattern matching (`==` glob), va xavfsizroq. 3. **Raqam operatorlari**: `-eq -ne -lt -le -gt -ge`. String uchun `=` va `!=`. `>=` va `<=` faqat `(( ))` arifmetikada. 4. **Fayl shartlari**: `-f` fayl, `-d` katalog, `-e` mavjud, `-r -w -x` ruxsatlar, `-s` bo'sh emas, `-z` string bo'sh. 5. **`case`** — ko'p variantli tanlovda `if/elif` zanjiridan toza va tezroq. `|` bilan bir necha pattern, `*` bilan wildcard, `*)` bilan default. !!! success "Keyingi qadam" Keyingi darsda — **sikllar** (`for`, `while`, `until`): bir shartni bilsangiz, uni takror bajarishni o'rganasiz. Fayllarni birma-bir qayta ishlash, serverlarni ro'yxatdan o'tkazish — hammasi sikllar bilan. --- ## Tekshiruv ro'yxati Bu darsni o'zlashtirdingizmi? Har bir bandni belgilang: - [ ] Men `if [ shart ]; then ... fi` tuzilmasini xatosiz yoza olaman. - [ ] Men `elif` va `else` ni bitta blokda to'g'ri tartibda qo'llaya olaman. - [ ] Men `[ ]` va `[[ ]]` orasidagi farqni tushuntira olaman va qachon qaysinisini tanlashni bilaman. - [ ] Men `-f`, `-d`, `-e`, `-r`, `-w`, `-x`, `-s`, `-z` operatorlarini ishlatib fayl va string tekshira olaman. - [ ] Men raqam shartlari uchun `-eq`, `-ne`, `-lt`, `-le`, `-gt`, `-ge` ni to'g'ri yoza olaman. - [ ] Men `case` blokini `;;` va `esac` bilan to'g'ri yopib, wildcard `*)` bilan default holat qo'sha olaman. - [ ] Men `case` da `|` bilan bir nechta patternni birlashtirib yoza olaman. - [ ] Men `[[ ]]` da `=~` yordamida regex tekshiruv yoza olaman.