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https://github.com/themattrix/bash-concurrent
Bash function to run tasks in parallel and display pretty output as they complete.
https://github.com/themattrix/bash-concurrent
Last synced: 4 days ago
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Bash function to run tasks in parallel and display pretty output as they complete.
- Host: GitHub
- URL: https://github.com/themattrix/bash-concurrent
- Owner: themattrix
- License: mit
- Created: 2016-01-12T06:32:17.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2019-04-16T14:50:50.000Z (almost 6 years ago)
- Last Synced: 2025-02-10T14:04:29.699Z (11 days ago)
- Language: Shell
- Homepage:
- Size: 88.9 KB
- Stars: 1,239
- Watchers: 26
- Forks: 54
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Concurrent    [](https://travis-ci.org/themattrix/bash-concurrent)
A Bash function to run tasks in parallel and display pretty output as they complete.
[](https://asciinema.org/a/34219)
## Examples
Run three tasks concurrently:
```bash
concurrent \
- 'My long task' sleep 10 \
- 'My medium task' sleep 5 \
- 'My short task' sleep 1
```
Run three tasks sequentially:
```bash
concurrent \
- 'My long task' sleep 10 \
- 'My medium task' sleep 5 \
- 'My short task' sleep 1 \
--sequential
```
Start the medium task *after* the short task succeeds:
```bash
concurrent \
- 'My long task' sleep 10 \
- 'My medium task' sleep 5 \
- 'My short task' sleep 1 \
--require 'My short task' \
--before 'My medium task'
```
Start the short task after *both* other tasks succeed:
```bash
concurrent \
- 'My long task' sleep 10 \
- 'My medium task' sleep 5 \
- 'My short task' sleep 1 \
--require 'My long task' \
--require 'My medium task' \
--before 'My short task'
```
Same as above, but shorter:
```bash
concurrent \
- 'My long task' sleep 10 \
- 'My medium task' sleep 5 \
- 'My short task' sleep 1 \
--require-all --before 'My short task'
```
Start the medium task *and* the long task after the short task succeeds:
```bash
concurrent \
- 'My long task' sleep 10 \
- 'My medium task' sleep 5 \
- 'My short task' sleep 1 \
--require 'My short task' \
--before 'My medium task' \
--before 'My long task'
```
Same as above, but shorter:
```bash
concurrent \
- 'My long task' sleep 10 \
- 'My medium task' sleep 5 \
- 'My short task' sleep 1 \
--require 'My short task' --before-all
```
Run the first two tasks concurrently,
*and then* the second two tasks concurrently,
*and then* the final three tasks concurrently.
```bash
concurrent \
- 'Task 1' sleep 3 \
- 'Task 2' sleep 3 \
--and-then \
- 'Task 3' sleep 3 \
- 'Task 4' sleep 3 \
--and-then \
- 'Task 5' sleep 3 \
- 'Task 6' sleep 3 \
- 'Task 7' sleep 3
```
If your command has a `-` argument, you can use a different task delimiter:
```bash
concurrent \
+ 'My long task' wget -O - ... \
+ 'My medium task' sleep 5 \
+ 'My short task' sleep 1
```
You can display extra information at the end of each task's status line by
echoing to `fd 3`.
```bash
my_task() {
...
echo "(extra info)" >&3
...
}
```
Take a look at [`demo.sh`](demo.sh) for more involved examples.
## Dry Run
If you have a lot of dependencies between tasks, it's generally a good idea to
perform a dry-run to ensure that the tasks are ordered as expected. Set the
`CONCURRENT_DRY_RUN` environment variable to perform a dry-run.
## Forking Limit
By default, `concurrent` allows up to 50 concurrently-running tasks.
Set the `CONCURRENT_LIMIT` environment variable to override this limit.
A neat trick is to set the limit to 1, essentially forcing a `--sequential`
run, but with existing tasks between dependencies taken into account.
A limit less than 1 is treated as no limit.
## Compact Display
If the number of tasks exceed the terminal height, the "compact display" will
be activated. It can also be explicitly activated by setting the
`CONCURRENT_COMPACT` environment variable to anything other than `0`.
In this mode, each task is represented by a single character instead of an
entire line. An execution summary is displayed above the tasks.
[](https://asciinema.org/a/37290)
## Non-Interactive Mode
If the output is not attached to a tty, the "non-interactive" mode will be
activated. It can also be explicitly activated by setting the
`CONCURRENT_NONINTERACTIVE` environment variable to anything other than `0`.
In this mode, each task is displayed as soon as it completes. Colors are
also disabled.
## Logging
By default, logs for each task will be created in `./logs//`.
For example:
$ ls .logs/2016-02-02@00:09:07
0. Creating VM (0).log
1. Creating ramdisk (0).log
2. Enabling swap (0).log
3. Populating VM with world data (1).log
4. Spigot: Pulling docker image for build (1).log
5. Spigot: Building JAR (skip).log
6. Pulling remaining docker images (skip).log
7. Launching services (skip).log
To change this directory, set `CONCURRENT_LOG_DIR` before calling `concurrent`.
## Failure Demo
[](https://asciinema.org/a/34217)
## Interrupted Demo
[](https://asciinema.org/a/34218)
## Requirements
- bash >= 4.2 (for `declare -g`)
- cat
- cp
- date
- mkdir
- mkfifo
- mktemp
- mv
- sed
- tail
- tput
## Change Log
- **2.4.0**
- *New:* Gracefully switches to non-interactive mode when a tty is not present or if `CONCURRENT_NONINTERACTIVE` is non-zero.
- **2.3.3**
- *Fix:* Cursor no longer hidden when running nested.
- **2.3.2**
- *Fix:* Failing tasks with no output now exit with the correct status (credit: @uluyol).
- **2.3.1**
- *Fix:* Now clearing to end of line when printing extra status info after a task (credit: @fragmede).
- **2.3.0**
- *New:* Concurrency limit defaults to 50, unless overridden by `CONCURRENT_LIMIT`.
- *New:* If the number of tasks exceed the terminal height (or `CONCURRENT_COMPACT` is set), each task will be displayed as a single character instead of a taking up an entire line.
- *New:* Cursor now hidden while running.
- *Fix:* Greatly improved speed of event loop. Especially noticeable for large numbers of tasks.
- *Fix:* Namespaced `command_*` and `prereq_*` arrays so that they don't carry into the tasks.
- **2.2.1**
- *Fix:* Tasks not allowed to read from stdin.
- **2.2.0**
- *New:* Instances of concurrent can be nested without breaking.
- *New:* Set custom log dir with `CONCURRENT_LOG_DIR`.
- *Fix:* Works under Cygwin (special thanks to @FredDeschenes).
- *Fix:* No longer requires GNU sed (gsed) on OS X.
- *Fix:* Animation now uses a single process.
- *Fix:* Extra status info is now merely bold instead of bold/white, which should be more visible on light terminal backgrounds.
- **2.1.0**
- *New:* New `--and-then` flag for dividing tasks into groups. All tasks in a group run concurrently, but all must complete before the next group may start (inspiration: [fooshards on Reddit](https://www.reddit.com/r/programming/comments/42n64o/concurrent_bash_function_to_run_tasks_in_parallel/czbxnrh)).
- *Fix:* Removed extra backslashes in README (credit: [bloody-albatross on Reddit](https://www.reddit.com/r/programming/comments/42n64o/concurrent_bash_function_to_run_tasks_in_parallel/czbrtjg))
- **2.0.1**
- *Fix:* `kill` is a bash builtin (credit: @ScoreUnder)
- *Fix:* Require GNU sed on OS X (credit: @kumon)
- *Fix:* Static analysis with shellcheck on push via Travis CI (credit: @xzovy)
- *Fix:* Cleaner signal handling.
- *Fix:* Simplified event loop.
- **2.0.0**
- *New:* Tasks can now display status updates by echoing to fd 3.
- **1.6.0**
- *New:* `CONCURRENT_DRY_RUN` environment variable runs `sleep 3` instead of actual commands (and prints message).
- **1.5.2**
- *Fix:* Requirement loops disallowed.
- **1.5.1**
- *Fix:* Task is not allowed to require itself directly.
- **1.5.0**
- *New:* First argument is now the task delimiter.
- **1.4.1**
- *Fix:* Namespaced previously-missed function.
- **1.4.0**
- *New:* New `--require-all` and `--before-all` flags.
- *Fix:* Namespaced all concurrent-related functions and variables.
- *Fix:* Unsetting all concurrent-related functions and variables in the task's context.
- *Fix:* Enforcing foreground in an interactive shell.
- **1.3.0**
- *New:* New `--sequential` flag, for when each task requires the previous.
- **1.2.0**
- *New:* Running tasks have an animated cursor.
- *Fix:* Enforcing bash version 4.3.
- *Fix:* Echo is re-enabled even if an internal error occurs.
- **1.1.6**
- *Fix:* Enforcing bash version 4.
- **1.1.5**
- *Fix:* Tasks now use original `$PWD` and `$OLDPWD`.
- **1.1.4**
- *Fix:* Tasks now use original `$SHELLOPTS` and `$BASHOPTS`.
- **1.1.3**
- *Fix:* Sanitizing forward slashes from log names.
- **1.1.2**
- *Fix:* Ensuring task status file exists even if an internal error occurs.
- **1.1.1**
- *Fix:* Task command may now have arguments starting with `-`.
- **1.1.0**
- *New:* Gracefully handling SIGINT.
- *Fix:* Works on OS X too.
- **1.0.0**
- Initial working release.