Parallel

parallel allows the user to execute shell scripts or commands in parallel.

Examples

aws ec2 describe-regions --query "Regions[].{Name:RegionName}" --output text | parallel "echo {}; aws ec2 describe-instances --region {}"

your_command | parallel "echo {}; your_command2 {}"

ls | parallel git -C {} fetch
ls | parallel git -C {} pull

Activities

Basic

1. Execute a command in parallel by ssh in MACHINE1 and MACHINE2 using parallel
2. Read stackexchange questions about gnu-parallel: https://unix.stackexchange.com/questions/tagged/gnu-parallel?tab=votes&pagesize=50
3. Install parallel in macOS: brew install parallel can conflict with brew install moreutils

Intermediate

1. Review different parallel options such as: --keep-order or -k which keep order in the output. Do not affect order of execution.
2. Update all your git repositories in a directory in macOS using parallel: ls | parallel git -C {} fetch

Related terms

• Parallels
• for
• pssh
• parallel --citation

See also

• parallel, for, xargs, parallel --citation, sshlogin
• xargs, parallel, paste, map
• moreutils package
• CPU, GPU, NPU, TPU, DPU, Groq, Proliant, thread (Pthreads), processor, CPU socket, core, ARM , CPU Virtualization, Intel, AMD, nm, lscpu, AVX-512, Passthrough, CPU intensive, Graviton processor, Branch predictor, vCPU, SSE, Power

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Source: https://en.wikiversity.org/wiki/Linux/Basic_commands/parallel