A sysadmin needs his tools. I really need at least 3 tools to be productive:
- Terminal-Emulator (or screen/tmux if I am working without X)
- Shell
- Editor
This is my Rule Of Three. Those 3 tools can make my life much easier. Therefore I have to choose those tools wisely. And of course I have to know them very well, so I can get all the benefits of them. The last time I wrote about rxvt(Terminal-Emulator). In this article I want to introduce one of my “favourite” shells: zsh
I have to say that I like the bash too. It is my rootshell and I am very used to the bash because I am using it for many years. Zsh on the other side is very customizable and has cool scripting-features, that’s why it became my standard usershell.
Customization
What’s really great about zsh is that it is highly customizable. The problem with “highly customizable” is mostly that things start to get complex. Luckily, there are frameworks to make this task more easy. One of them is oh-my-zsh. It’s loaded via your .zshrc and comes with lot’s of plugins for autocompletion and themes. Just try it, it’s great!
Autoload long commands in you editor
If you just typed in a very long command in your shell and you want this command copied in your favourite editor($EDITOR) then just type <CTRL>+X <CTRL>+E
Builtin Pager
zsh has a builtin pager. If you want to read a (text)file just type:
< sometextfile.txt
History search
Most bash-user know “ <STRG>+<r>” for recursively search the history. If you want to search the history for a command you can use the <UP> key. Let’s assume we are looking for one of our last ssh commands, then we can simply type ssh <UP>
Tab completion
Autocomplete cd
One of the cool things in zsh is tab completion. If you type “cd <TAB>” it looks like this:
You can navigate using <TAB> or any <ARROW-KEY> through this menu, or just type the first letter of one directory and press <TAB> again…
Smart completion of a path
You can also shortcut a path. Let’s assume you have a path like this:
arch/openrisc/kernel
Then you can just type:
a/o/k
..hit <TAB> and zsh will autocomplete your command, or ask you if there are more than one directories with the same letter.
Autocomplete commands
Zsh can even autocomplete commands and command-line-arguments. Autocompletion is highly configurable but also quite complex. I would recommend to use oh-my-zsh for this.
Some Command-completes I really like are:
- This comes with oh-my-zsh:
git <TAB> or git co<TAB> - Get a list of your /etc/hosts:
ssh root@<TAB> - Get a list of arguments of vim:
vim -<TAB> - Get a list of processes to kill:
kill <TAB>
Sophisticated Globbing
Globbing means searching files in your filesystem by using wildcards. This will search in your working directory and execute ls with all files(and directories) beginning with z :
➜ Documentation ls z*
zorro.txt
zh_CN:
arm filesystems magic-number.txt stable_kernel_rules.txt
arm64 gpio.txt oops-tracing.txt SubmittingDrivers
basic_profiling.txt HOWTO SecurityBugs SubmittingPatches
CodingStyle io_ordering.txt sparse.txt video4linux
email-clients.txt IRQ.txt stable_api_nonsense.txt volatile-considered-harmful.txt
With zsh you can also glob recursively
➜ linux-4.2.4 ls **/*.pl
arch/arm/crypto/bsaes-armv7.pl
arch/arm/crypto/sha256-armv4.pl
arch/arm/crypto/sha512-armv4.pl
Documentation/filesystems/cifs/winucase_convert.pl
Documentation/trace/postprocess/trace-pagealloc-postprocess.pl
Documentation/trace/postprocess/trace-vmscan-postprocess.pl
Documentation/video4linux/extract_xc3028.pl
drivers/crypto/vmx/aesp8-ppc.pl
drivers/crypto/vmx/ghashp8-ppc.pl
drivers/crypto/vmx/ppc-xlate.pl
drivers/scsi/script_asm.pl
drivers/usb/serial/ezusb_convert.pl
scripts/bootgraph.pl
scripts/checkincludes.pl
scripts/checkpatch.pl
scripts/checkstack.pl
scripts/checkversion.pl
scripts/export_report.pl
scripts/get_maintainer.pl
scripts/headerdep.pl
scripts/headers_check.pl
scripts/kconfig/streamline_config.pl
scripts/markup_oops.pl
scripts/namespace.pl
scripts/profile2linkerlist.pl
scripts/recordmcount.pl
tools/perf/scripts/perl/check-perf-trace.pl
tools/perf/scripts/perl/failed-syscalls.pl
tools/perf/scripts/perl/rw-by-file.pl
tools/perf/scripts/perl/rw-by-pid.pl
tools/perf/scripts/perl/rwtop.pl
tools/perf/scripts/perl/wakeup-latency.pl
tools/testing/ktest/compare-ktest-sample.pl
tools/testing/ktest/ktest.pl
Replace find
Sometimes we need to find some files and execute commands using the search-results as arguments. For example find all files with permissions 444 and move them to /tmp:
find . -perm -444 -exec mv {} /tmp \;
We can do this in zsh using the following command:
mv **/*(rAR) /tmp
r means “u+r”, A means “g+r” and R means “o+r”.
Finding files owned by root:
ls **/*(u:root:)
Finding files owned by root and with user-executable set:
ls -l **/*(u:root:x)
A complete list of available expansion-commands can be found in the manual page:
man zshexp
Scripting
Zsh has lots of modules which can be loaded, it supports arrays and has lots of nice builtin features. A good point to get some overview are zsh-lovers.
Make zsh bash-compatible
By default zsh is not compatible with bash. if you need it bash-compatible just type:
emulate sh
Builtin Tetris
Last but not least: zsh has it’s builtin tetris!!! Type the following commands:
autoload -U tetris
zle -N tetris
bindkey ^h tetris
.. and hit
Conclusion
Zsh is fully customizable and very handy. Whenever I open its manual pages, i’ll find new cool features. Zsh improves my workflows, that’s why I love using it.
