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[Home](https://linuxize.com/) 2. / [bash](https://linuxize.com/tags/bash/) 3. / Bash For Loop: Syntax and Examples # Bash For Loop: Syntax and Examples By [Dejan Panovski](https://linuxize.com/authors/dejan-panovski/) • Updated on Mar 2, 2026 • 8 min read Series progress [Bash Scripting Fundamentals](https://linuxize.com/series/bash-scripting-fundamentals/) Part 26 of 39 On this page - [The Standard Bash `for` Loop](https://linuxize.com/post/bash-for-loop/#the-standard-bash-for-loop) - [Loop Over Strings](https://linuxize.com/post/bash-for-loop/#loop-over-strings) - [Loop Over a Range](https://linuxize.com/post/bash-for-loop/#loop-over-a-range) - [Loop Over Array Elements](https://linuxize.com/post/bash-for-loop/#loop-over-array-elements) - [The C-style `for` Loop](https://linuxize.com/post/bash-for-loop/#the-c-style-for-loop) - [Nested Loops](https://linuxize.com/post/bash-for-loop/#nested-loops) - [Controlling Loop Flow: `break` and `continue`](https://linuxize.com/post/bash-for-loop/#controlling-loop-flow-break-and-continue) - [`break` – Terminate the Loop](https://linuxize.com/post/bash-for-loop/#break--terminate-the-loop) - [`continue` – Skip to the Next Iteration](https://linuxize.com/post/bash-for-loop/#continue--skip-to-the-next-iteration) - [Real-World Examples](https://linuxize.com/post/bash-for-loop/#real-world-examples) - [Rename Files with Spaces in the Name](https://linuxize.com/post/bash-for-loop/#rename-files-with-spaces-in-the-name) - [Change File Extension](https://linuxize.com/post/bash-for-loop/#change-file-extension) - [Restart Multiple Docker Containers](https://linuxize.com/post/bash-for-loop/#restart-multiple-docker-containers) - [Troubleshooting](https://linuxize.com/post/bash-for-loop/#troubleshooting) - [Quick Reference](https://linuxize.com/post/bash-for-loop/#quick-reference) - [FAQ](https://linuxize.com/post/bash-for-loop/#faq) - [Conclusion](https://linuxize.com/post/bash-for-loop/#conclusion) Show full outline Share  Loops are a fundamental concept in programming languages. They allow you to execute a series of commands repeatedly until a specific condition is met. In scripting languages like Bash, loops are especially useful for automating repetitive tasks, eliminating the need to duplicate code. There are three basic loop constructs in Bash scripting: `for` loop, [`while` loop](https://linuxize.com/post/bash-while-loop/) , and [`until` loop](https://linuxize.com/post/bash-until-loop/) . This guide focuses on the `for` loop in Bash, including its syntax variations, nesting, flow-control statements like `break` and `continue`, and practical examples. ## The Standard Bash `for` Loop [\#](https://linuxize.com/post/bash-for-loop/#the-standard-bash-for-loop) The `for` loop iterates over a list of items and performs the given set of commands. The basic Bash `for` loop syntax is: txt ``` for item in [LIST] do [COMMANDS] done ``` The `[LIST]` can be a series of strings separated by spaces, a range of numbers, command output, an array, command-line arguments, and so on. ### Loop Over Strings [\#](https://linuxize.com/post/bash-for-loop/#loop-over-strings) The example below shows a loop that iterates over a list of strings. The loop operates on each item in the list, and the variable `element` stores the item that the loop is currently processing. sh ``` for element in Hydrogen Helium Lithium Beryllium do echo "Element: $element" done ``` output ``` Element: Hydrogen Element: Helium Element: Lithium Element: Beryllium ``` ### Loop Over a Range [\#](https://linuxize.com/post/bash-for-loop/#loop-over-a-range) You can use the sequence expression to [specify a range](https://linuxize.com/post/bash-sequence-expression/) of numbers or characters by defining the start and end point of the range. The sequence expression takes the following form: txt ``` {START..END} ``` Here is an example loop that iterates through all numbers from 0 to 3: sh ``` for i in {0..3} do echo "Number: $i" done ``` output ``` Number: 0 Number: 1 Number: 2 Number: 3 ``` Bash also supports specifying an increment when using ranges: txt ``` {START..END..INCREMENT} ``` Here is an example showing how to increment by 5: sh ``` for i in {0..20..5} do echo "Number: $i" done ``` output ``` Number: 0 Number: 5 Number: 10 Number: 15 Number: 20 ``` ### Loop Over Array Elements [\#](https://linuxize.com/post/bash-for-loop/#loop-over-array-elements) You can use the `for` loop to iterate over the elements of a [Bash array](https://linuxize.com/post/bash-arrays/) . In the example below, we define an array named `BOOKS` and iterate over each element of the array. sh ``` BOOKS=('In Search of Lost Time' 'Don Quixote' 'Ulysses' 'The Great Gatsby') for book in "${BOOKS[@]}"; do echo "Book: $book" done ``` output ``` Book: In Search of Lost Time Book: Don Quixote Book: Ulysses Book: The Great Gatsby ``` ## The C-style `for` Loop [\#](https://linuxize.com/post/bash-for-loop/#the-c-style-for-loop) Bash also supports a C-style `for` loop syntax: txt ``` for ((INITIALIZATION; TEST; STEP)) do [COMMANDS] done ``` The `INITIALIZATION` part is executed only once when the loop starts. Then, the `TEST` part is evaluated using [comparison operators](https://linuxize.com/post/bash-comparison-operators/) . If it is false, the loop is terminated. If the `TEST` is true, commands inside the body of the `for` loop are executed, and the `STEP` part is updated. In the following example, the loop starts by initializing `i = 0` and, before each iteration, checks whether `i ≤ 10`. If true, it [prints](https://linuxize.com/post/echo-command-in-linux-with-examples/) the current value of `i` and increments `i` by 1 (`i++`). Otherwise, the loop terminates. sh ``` for ((i = 0 ; i <= 10 ; i++)); do echo "Counter: $i" done ``` The loop iterates 11 times and produces the following output: output ``` Counter: 0 Counter: 1 Counter: 2 ... Counter: 8 Counter: 9 Counter: 10 ``` ## Nested Loops [\#](https://linuxize.com/post/bash-for-loop/#nested-loops) A nested loop is a loop inside another loop. You can nest loops to any depth. In a nested `for` loop, the inner loop runs a complete cycle of its iterations for every outer loop iteration. Here is an example that copies three files one by one to three servers: sh ``` for f in file_{1..3}; do for j in server_{1..3}; do echo "Copying file $f to server $j" # command to copy files done done ``` output ``` Copying file file_1 to server server_1 Copying file file_1 to server server_2 Copying file file_1 to server server_3 Copying file file_2 to server server_1 Copying file file_2 to server server_2 Copying file file_2 to server server_3 Copying file file_3 to server server_1 Copying file file_3 to server server_2 Copying file file_3 to server server_3 ``` ## Controlling Loop Flow: `break` and `continue` [\#](https://linuxize.com/post/bash-for-loop/#controlling-loop-flow-break-and-continue) The [`break` and `continue` statements](https://linuxize.com/post/bash-break-continue/) are used to control the execution of a `for` loop. ### `break` – Terminate the Loop [\#](https://linuxize.com/post/bash-for-loop/#break--terminate-the-loop) The `break` statement terminates the current loop and passes control to the statement that follows it. It is generally used to exit the loop when a specific condition is met. In the following example, the [`if` statement](https://linuxize.com/post/bash-if-else-statement/) terminates the loop once the current item is equal to `Lithium`: sh ``` for element in Hydrogen Helium Lithium Beryllium; do if [[ "$element" == 'Lithium' ]]; then break fi echo "Element: $element" done echo 'All Done!' ``` output ``` Element: Hydrogen Element: Helium All Done! ``` ### `continue` – Skip to the Next Iteration [\#](https://linuxize.com/post/bash-for-loop/#continue--skip-to-the-next-iteration) The `continue` statement exits the current iteration and passes control to the next one. In the following example, when the current item equals `2`, the `continue` statement skips the `echo` and moves to the next iteration: sh ``` for i in {1..5}; do if [[ "$i" == '2' ]]; then continue fi echo "Number: $i" done ``` output ``` Number: 1 Number: 3 Number: 4 Number: 5 ``` ## Real-World Examples [\#](https://linuxize.com/post/bash-for-loop/#real-world-examples) ### Rename Files with Spaces in the Name [\#](https://linuxize.com/post/bash-for-loop/#rename-files-with-spaces-in-the-name) The following example renames all files in the current directory that contain a space, replacing spaces with underscores: sh ``` for file in *\ *; do mv "$file" "${file// /_}" done ``` - `*\ *` matches all filenames that contain a space. - `${file// /_}` uses [shell parameter expansion](https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html) to replace every space with an underscore. ### Change File Extension [\#](https://linuxize.com/post/bash-for-loop/#change-file-extension) The following example [renames all files](https://linuxize.com/post/how-to-rename-files-in-linux/) ending in `.jpeg` in the current directory, replacing the extension with `.jpg`: sh ``` for file in *.jpeg; do mv -- "$file" "${file%.jpeg}.jpg" done ``` - `*.jpeg` matches all `.jpeg` files in the current directory. - `${file%.jpeg}` strips the `.jpeg` suffix using shell parameter expansion, and `.jpg` is appended to form the new name. - The `--` flag prevents `mv` from misinterpreting filenames that start with a dash as options. ### Restart Multiple Docker Containers [\#](https://linuxize.com/post/bash-for-loop/#restart-multiple-docker-containers) Here is an example that restarts a list of containers after deploying new code: sh ``` for container in web db cache redis; do docker restart "$container" && echo "Restarted $container" done ``` Containers are passed to the loop as a list of strings. ## Troubleshooting [\#](https://linuxize.com/post/bash-for-loop/#troubleshooting) **Loop splits a filename or string with spaces into multiple items** Without quotes, Bash performs word splitting on spaces. Always quote variables and array expansions: use `"${ARRAY[@]}"` instead of `${ARRAY[@]}`, and `"$file"` instead of `$file`. **Glob pattern in the list expands unexpectedly** When a glob pattern like `*.jpeg` matches no files, Bash passes the literal string `*.jpeg` to the loop variable. Add `shopt -s nullglob` before the loop to make unmatched globs expand to nothing instead. **C-style loop does not behave like expected with `[[ ]]`** The C-style loop uses arithmetic evaluation — comparisons inside `(( ))` use `<`, `>`, and `==` directly. Do not mix `[[ ]]` test syntax inside the loop initializer or condition. **Range with a variable does not expand** Brace expansion happens before variable substitution, so `{1..$N}` does not work. Use a C-style loop or `seq` instead: `for i in $(seq 1 "$N"); do`. ## Quick Reference [\#](https://linuxize.com/post/bash-for-loop/#quick-reference) | Syntax | Description | |---|---| | `for item in a b c; do ... done` | Loop over a list of strings | | `for i in {1..10}; do ... done` | Loop over a numeric range | | `for i in {0..20..5}; do ... done` | Loop over a range with increment | | `for item in "${ARRAY[@]}"; do ... done` | Loop over array elements | | `for ((i=0; i<10; i++)); do ... done` | C-style loop | | `break` | Exit the loop immediately | | `continue` | Skip to the next iteration | ## FAQ [\#](https://linuxize.com/post/bash-for-loop/#faq) **What is the difference between the standard `for` loop and the C-style `for` loop?** The standard `for` loop iterates over a list of items (strings, array elements, a range). The C-style `for` loop uses arithmetic initialization, condition, and step expressions — it is better suited for counter-based iteration where you control the start, end, and step explicitly. **How do I loop over lines in a file?** Use a `while` loop with `read` instead: `while IFS= read -r line; do echo "$line"; done < file.txt`. A `for` loop is not suited for line-by-line file reading because it splits on whitespace, not newlines. **Can I use `break` or `continue` in nested loops?** Yes. By default, `break` and `continue` affect only the innermost loop. To exit an outer loop from an inner one, use a numeric argument: `break 2` exits two levels of nesting. **How do I loop over command-line arguments?** Use `for arg in "$@"; do` to iterate over all positional parameters passed to the script. ## Conclusion [\#](https://linuxize.com/post/bash-for-loop/#conclusion) The Bash `for` loop iterates over a list of items or runs for a defined number of iterations using C-style syntax. Combined with `break`, `continue`, nesting, and parameter expansion, it enables elegant solutions to many automation tasks. To learn all the ways to run your scripts, see [How to Run a Bash Script](https://linuxize.com/post/run-bash-script/) . If you have any questions, feel free to leave a comment below. ## Tags [bash](https://linuxize.com/tags/bash/) ## Linuxize Weekly Newsletter A quick weekly roundup of new tutorials, news, and tips. ## About the authors  Dejan Panovski Dejan Panovski is the founder of Linuxize, an RHCSA-certified Linux system administrator and DevOps engineer based in Skopje, Macedonia. Author of 800+ Linux tutorials with 20+ years of experience turning complex Linux tasks into clear, reliable guides. [View author page](https://linuxize.com/authors/dejan-panovski/) ## [Bash Scripting Fundamentals](https://linuxize.com/series/bash-scripting-fundamentals/) [View all parts](https://linuxize.com/series/bash-scripting-fundamentals/) Part 26 of 39 [Previous · Part 25 Bash Range: Sequence Expression Syntax and Examples](https://linuxize.com/post/bash-sequence-expression/) [Next · Part 27 Bash while Loop: Syntax and Examples](https://linuxize.com/post/bash-while-loop/) ## More Like This - [How to Parse Command-Line Options in Bash with getopts](https://linuxize.com/post/bash-getopts/) - [Bash Positional Parameters](https://linuxize.com/post/bash-positional-parameters/) - [Bash Scripting Fundamentals](https://linuxize.com/series/bash-scripting-fundamentals/) - [Bash Comparison Operators](https://linuxize.com/post/bash-comparison-operators/) - [How to Run a Bash Script in Linux](https://linuxize.com/post/run-bash-script/) ## You May Also Like [Feb 28, 2026 • 6 min read How to Create Bash Aliases Learn how to create permanent and temporary bash aliases on Linux. This guide covers alias syntax, persistent aliases in .bashrc, and functions that accept arguments.](https://linuxize.com/post/how-to-create-bash-aliases/) [Feb 27, 2026 • 6 min read Bash while Loop: Syntax and Examples The Bash while loop repeatedly executes a block of commands as long as a condition is true. This guide covers the syntax, infinite loops, reading files line by line, and the break and continue statements.](https://linuxize.com/post/bash-while-loop/) [Feb 11, 2026 • 9 min read How to Parse Command-Line Options in Bash with getopts This guide explains how to parse command-line options in Bash with getopts, including option strings, OPTARG and OPTIND, error handling, and practical script examples.](https://linuxize.com/post/bash-getopts/) ## Comments © 2026 Linuxize.com \| A Raptive Partner Site [Write For Us](https://linuxize.com/write-for-us/) [Support Us](https://linuxize.com/donate/) [Privacy Policy](https://linuxize.com/privacy-policy/) [Editorial Policy](https://linuxize.com/editorial-policy/) [Terms](https://linuxize.com/terms-of-service/) [Contact](https://linuxize.com/contact/)

Loops are a fundamental concept in programming languages. They allow you to execute a series of commands repeatedly until a specific condition is met. In scripting languages like Bash, loops are especially useful for automating repetitive tasks, eliminating the need to duplicate code. There are three basic loop constructs in Bash scripting: `for` loop, [`while` loop](https://linuxize.com/post/bash-while-loop/) , and [`until` loop](https://linuxize.com/post/bash-until-loop/) . This guide focuses on the `for` loop in Bash, including its syntax variations, nesting, flow-control statements like `break` and `continue`, and practical examples. ## The Standard Bash `for` Loop The `for` loop iterates over a list of items and performs the given set of commands. The basic Bash `for` loop syntax is: The `[LIST]` can be a series of strings separated by spaces, a range of numbers, command output, an array, command-line arguments, and so on. ### Loop Over Strings The example below shows a loop that iterates over a list of strings. The loop operates on each item in the list, and the variable `element` stores the item that the loop is currently processing. ### Loop Over a Range You can use the sequence expression to [specify a range](https://linuxize.com/post/bash-sequence-expression/) of numbers or characters by defining the start and end point of the range. The sequence expression takes the following form: Here is an example loop that iterates through all numbers from 0 to 3: Bash also supports specifying an increment when using ranges: Here is an example showing how to increment by 5: ### Loop Over Array Elements You can use the `for` loop to iterate over the elements of a [Bash array](https://linuxize.com/post/bash-arrays/) . In the example below, we define an array named `BOOKS` and iterate over each element of the array. ## The C-style `for` Loop Bash also supports a C-style `for` loop syntax: The `INITIALIZATION` part is executed only once when the loop starts. Then, the `TEST` part is evaluated using [comparison operators](https://linuxize.com/post/bash-comparison-operators/) . If it is false, the loop is terminated. If the `TEST` is true, commands inside the body of the `for` loop are executed, and the `STEP` part is updated. In the following example, the loop starts by initializing `i = 0` and, before each iteration, checks whether `i ≤ 10`. If true, it [prints](https://linuxize.com/post/echo-command-in-linux-with-examples/) the current value of `i` and increments `i` by 1 (`i++`). Otherwise, the loop terminates. The loop iterates 11 times and produces the following output: ## Nested Loops A nested loop is a loop inside another loop. You can nest loops to any depth. In a nested `for` loop, the inner loop runs a complete cycle of its iterations for every outer loop iteration. Here is an example that copies three files one by one to three servers: ## Controlling Loop Flow: `break` and `continue` The [`break` and `continue` statements](https://linuxize.com/post/bash-break-continue/) are used to control the execution of a `for` loop. ### `break` – Terminate the Loop The `break` statement terminates the current loop and passes control to the statement that follows it. It is generally used to exit the loop when a specific condition is met. In the following example, the [`if` statement](https://linuxize.com/post/bash-if-else-statement/) terminates the loop once the current item is equal to `Lithium`: ### `continue` – Skip to the Next Iteration The `continue` statement exits the current iteration and passes control to the next one. In the following example, when the current item equals `2`, the `continue` statement skips the `echo` and moves to the next iteration: ## Real-World Examples ### Rename Files with Spaces in the Name The following example renames all files in the current directory that contain a space, replacing spaces with underscores: - `*\ *` matches all filenames that contain a space. - `${file// /_}` uses [shell parameter expansion](https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html) to replace every space with an underscore. ### Change File Extension The following example [renames all files](https://linuxize.com/post/how-to-rename-files-in-linux/) ending in `.jpeg` in the current directory, replacing the extension with `.jpg`: - `*.jpeg` matches all `.jpeg` files in the current directory. - `${file%.jpeg}` strips the `.jpeg` suffix using shell parameter expansion, and `.jpg` is appended to form the new name. - The `--` flag prevents `mv` from misinterpreting filenames that start with a dash as options. ### Restart Multiple Docker Containers Here is an example that restarts a list of containers after deploying new code: Containers are passed to the loop as a list of strings. ## Troubleshooting **Loop splits a filename or string with spaces into multiple items** Without quotes, Bash performs word splitting on spaces. Always quote variables and array expansions: use `"${ARRAY[@]}"` instead of `${ARRAY[@]}`, and `"$file"` instead of `$file`. **Glob pattern in the list expands unexpectedly** When a glob pattern like `*.jpeg` matches no files, Bash passes the literal string `*.jpeg` to the loop variable. Add `shopt -s nullglob` before the loop to make unmatched globs expand to nothing instead. **C-style loop does not behave like expected with `[[ ]]`** The C-style loop uses arithmetic evaluation — comparisons inside `(( ))` use `<`, `>`, and `==` directly. Do not mix `[[ ]]` test syntax inside the loop initializer or condition. **Range with a variable does not expand** Brace expansion happens before variable substitution, so `{1..$N}` does not work. Use a C-style loop or `seq` instead: `for i in $(seq 1 "$N"); do`. ## Quick Reference | Syntax | Description | |---|---| | `for item in a b c; do ... done` | Loop over a list of strings | | `for i in {1..10}; do ... done` | Loop over a numeric range | | `for i in {0..20..5}; do ... done` | Loop over a range with increment | | `for item in "${ARRAY[@]}"; do ... done` | Loop over array elements | | `for ((i=0; i<10; i++)); do ... done` | C-style loop | | `break` | Exit the loop immediately | | `continue` | Skip to the next iteration | ## FAQ **What is the difference between the standard `for` loop and the C-style `for` loop?** The standard `for` loop iterates over a list of items (strings, array elements, a range). The C-style `for` loop uses arithmetic initialization, condition, and step expressions — it is better suited for counter-based iteration where you control the start, end, and step explicitly. **How do I loop over lines in a file?** Use a `while` loop with `read` instead: `while IFS= read -r line; do echo "$line"; done < file.txt`. A `for` loop is not suited for line-by-line file reading because it splits on whitespace, not newlines. **Can I use `break` or `continue` in nested loops?** Yes. By default, `break` and `continue` affect only the innermost loop. To exit an outer loop from an inner one, use a numeric argument: `break 2` exits two levels of nesting. **How do I loop over command-line arguments?** Use `for arg in "$@"; do` to iterate over all positional parameters passed to the script. ## Conclusion The Bash `for` loop iterates over a list of items or runs for a defined number of iterations using C-style syntax. Combined with `break`, `continue`, nesting, and parameter expansion, it enables elegant solutions to many automation tasks. To learn all the ways to run your scripts, see [How to Run a Bash Script](https://linuxize.com/post/run-bash-script/) . If you have any questions, feel free to leave a comment below. Tags Linuxize Weekly Newsletter A quick weekly roundup of new tutorials, news, and tips. About the authors  Dejan Panovski Dejan Panovski is the founder of Linuxize, an RHCSA-certified Linux system administrator and DevOps engineer based in Skopje, Macedonia. Author of 800+ Linux tutorials with 20+ years of experience turning complex Linux tasks into clear, reliable guides. [View author page](https://linuxize.com/authors/dejan-panovski/) Part 26 of 39