We needed a GNU/Linux command line formatter to beautify a huge JSON file we received. A solution we got our hands on was the json — JSON encoder and decoder. The usage was extremely easy and fast:
1 | python -mjson.tool ugly.json > beautiful.json; |
Recently we were processing some results from an SQL query on the command line, we were grouping the results based on the first column of the query results and we wanted to add an empty line between each group of data.
Instead of messing with SQL specifics, we decided to use awk to finish the task which resulted in the following code:
awk -F '|' -v column=1 'NR>1 && $column != previous { print "" } { previous = $column } { print $0 }'
-F fs or --field-separator fs: This option allowed us to choose the input field separator, in other words the character that should be used to split our text into columns. We used the value | because that character is the default column delimiter for sqlite.-v var=val or --assign var=val: We used the -v option to define a variable to be used later on in the script. The value 1 was assigned to the variable column before execution of the program began and it was available event to the BEGIN rule of the AWK program. We did this to make the code a bit more modular, we could have just hardcoded the number in.NR>1 && $column != previous { print "" } : Here we defined an if statement that checks two options: First we make sure that we are not on the first line of the input by using the NR>1 (and thus avoid creating an empty line which will be the first line of the output).previous, it is on the next step). When both statements are true (we are not on the first row and the value of the column in the current row is different than the value of the column in the previous row) it will print out an empty line.{ previous = $column }: This part is executed on ALL lines (even the first one) no matter what the values are. What this line does is to translate the value of the column variable from being a number (the index of the column that we are interested in) into the actual value that the column has at that specific line. That value is then copied to the previous variable to allow us to perform the check in the previous point once we move to the next line.{ print $0 }: Finally, this part is also executed on all lines and it instructs awk to print the input row whole and as is. This whole part could be replaced by a true value like the value 1. In awk as you see in this example, you define a series of operations. Each operation is constructed by a pattern to be matched and an action. Each pattern is evaluated for each input line, and in the cases where the pattern matches, the action is executed. The user can choose to omit either the pattern or the action for any operation. When a pattern is omitted, the action is executed on every line. When the action is omitted, then awk will execute { print $0 }. So, by adding a true value on its own it will be translated as on each line execute { print $0 } which prints the whole row as is.1|1|0.0564904019731175 1|2|0.103176086258974 1|3|0.12910406904073 1|4|0.188592489201024 1|5|0.169676224898487 1|6|0.164690820027741 1|7|0.128458728519047 1|8|0.18549773544014 1|9|0.155677575617836 1|10|0.153941343314285 2|1|0.217221158956016 2|2|0.23390973064067 2|3|0.180231657220626 2|4|0.257673927303071 2|5|0.261393785194329 2|6|0.273441488895552 2|7|0.242815632929545 2|8|0.262269697286057 2|9|0.256054399760891 2|10|0.262613705138411 3|1|0.378589461360716 3|2|0.33008177312116 3|3|0.380973166776554 3|4|0.340431190160728 3|5|0.38189416214207 3|6|0.364842933594872 3|7|0.372958396398964 3|8|0.350010176652464 3|9|0.355815612501188 3|10|0.380553180349294
Will become
1|1|0.0564904019731175 1|2|0.103176086258974 1|3|0.12910406904073 1|4|0.188592489201024 1|5|0.169676224898487 1|6|0.164690820027741 1|7|0.128458728519047 1|8|0.18549773544014 1|9|0.155677575617836 1|10|0.153941343314285 2|1|0.217221158956016 2|2|0.23390973064067 2|3|0.180231657220626 2|4|0.257673927303071 2|5|0.261393785194329 2|6|0.273441488895552 2|7|0.242815632929545 2|8|0.262269697286057 2|9|0.256054399760891 2|10|0.262613705138411 3|1|0.378589461360716 3|2|0.33008177312116 3|3|0.380973166776554 3|4|0.340431190160728 3|5|0.38189416214207 3|6|0.364842933594872 3|7|0.372958396398964 3|8|0.350010176652464 3|9|0.355815612501188 3|10|0.380553180349294
Recently we were working on a bash script that was supposed to find and process some files that matched certain criteria. The script would process the files one by one and the criteria would be matched using the find command. To implement our solution, we returned the results of the find back to the for loop in an attempt to keep it simple and human readable.
Our original code was the following:
(do not use it, see explanation below)
1 2 3 4 | for file in `find $search_path -type f -name '*.kml'`; do # Formatting KML file to be human friendly. xmllint --format "$file" > "$output_path/$file";done |
Soon we realized that we had a very nasty bug, the way we formatted the command it would break filenames that had spaces in them into multiple for loop entries and thus we would get incorrect filenames back to process.
To solve this issue we needed a way to force our loop to read the results of find one line at a time instead of one word at a time. The solution we used in the end was fairly different than the original code as it had the following significant changes:
find command were piped into the loopfor loop and a while loop was used insteadread command that reads one line at a time to fill in the filename variable-r parameter does not allow backslashes to escape any characters) 1 2 3 4 5 | find $search_path -type f -name '*.kml' | while read -r file; do # Formatting KML file to be human friendly. xmllint --format "$file" > "$output_path/$file";done |
The following terminator layout ([download id=”4658″]) opens 3 different tabs, the first two tabs contain only one terminal each and the third one has 4 terminals in a 2×2 matrix.
Each of these tabs have their own custom name set and following each terminal has its name set to make it easier for the user to recognize the purpose of each one.
[download id=”4658″]
After opening these terminals, the configuration file, contains specific commands to be executed by each terminal, allowing you to automate a some trivial part of your day to day operations.
In this example, each terminal will navigate to a specific project or connect via ssh to some server, then it will perform some operation like performing a git pull and finally it will preserve the connection for you by starting a new bash instance to continue using that terminal.
Feel free to edit the layout and create a custom configuration for your tabs / the terminals and the commands.
config ([download id=”4658″]) file in your home user folder ~/.config/terminator/ with the one we providenautilus press Ctrl+H to view hidden files and folders if you cannot find the .config folder)terminator -l init;If you want to create an alias for this command:
Open .bashrc file at your home user folder and add the following
alias my-init="terminator -l init"
For any new terminal in terminator, executing my-init will spawn a new window of terminator that has all the configuration from the file loaded into it.
[global_config]
[keybindings]
[layouts]
[[default]]
[[[child1]]]
parent = window0
type = Terminal
[[[window0]]]
parent = ""
type = Window
[[init]]
[[[child0]]]
fullscreen = False
last_active_window = True
maximised = True
order = 0
parent = ""
position = 0:26
size = 1918, 1002
title = /bin/bash
type = Window
[[[child1]]]
active_page = 0
labels = www, MA, all other, dev logs, staging logs, live logs
last_active_term = d3c317d7-964a-4625-96d0-39deb5166072, 93ce7874-059e-4794-b337-7b640654a3d6, db090e6f-07e4-431e-ad86-a8b6cb965b5e, 906a5f4d-a3af-4da8-8385-673b132e7edd, 1b48b3b9-216c-470b-be53-ec1e8c6fdc0b, cb7d737c-a064-4e0e-ad5e-59c47d7bdd3b
order = 0
parent = child0
type = Notebook
[[[child11]]]
order = 3
parent = child1
position = 956
ratio = 0.500261643119
type = HPaned
[[[child14]]]
order = 4
parent = child1
position = 956
ratio = 0.500261643119
type = HPaned
[[[child17]]]
order = 5
parent = child1
position = 956
ratio = 0.500261643119
type = HPaned
[[[child4]]]
order = 2
parent = child1
position = 956
ratio = 0.500261643119
type = HPaned
[[[child5]]]
order = 0
parent = child4
position = 481
ratio = 0.500520291363
type = VPaned
[[[child8]]]
order = 1
parent = child4
position = 481
ratio = 0.500520291363
type = VPaned
[[[terminal10]]]
command = cd /vhosts/www.example.com/; git pull; bash
order = 1
parent = child8
profile = default
title = www.example.com
type = Terminal
uuid = db090e6f-07e4-431e-ad86-a8b6cb965b5e
[[[terminal12]]]
command = "ssh -t git 'cd vhosts/www.bytefreaks.net/ci_applications/registration_forms/logs/; ll; bash'"
directory = ""
order = 0
parent = child11
profile = default
title = WWW dev logs
type = Terminal
uuid = 4c08356b-b516-4286-8b6d-ba071f1394f3
[[[terminal13]]]
command = "ssh -t git 'cd vhosts/my.bytefreaks.net/symfony/var/logs/; ll; bash'"
directory = ""
order = 1
parent = child11
profile = default
title = MA dev logs
type = Terminal
uuid = 906a5f4d-a3af-4da8-8385-673b132e7edd
[[[terminal15]]]
command = "ssh -t web13 'cd /data/var/www/vhosts/staging-www.bytefreaks.net/htdocs/ci_applications/registration_forms/logs/; ls -la; bash'"
order = 0
parent = child14
profile = default
title = WWW staging logs
type = Terminal
uuid = 1b48b3b9-216c-470b-be53-ec1e8c6fdc0b
[[[terminal16]]]
command = "ssh -t web13 'cd /data/var/www/vhosts/staging-my.bytefreaks.net/htdocs/symfony/var/logs/; ls -la; bash'"
order = 1
parent = child14
profile = default
title = MA staging logs
type = Terminal
uuid = e26e94cd-855a-44ff-9c67-66b1c03bac56
[[[terminal18]]]
command = "ssh -t web13 'cd /data/var/www/vhosts/www.bytefreaks.net/htdocs/ci_applications/registration_forms/logs/; ls -la; bash'"
directory = ""
order = 0
parent = child17
profile = default
title = WWW Live logs
type = Terminal
uuid = 70466609-2d01-45d2-84b4-e377b111e540
[[[terminal19]]]
command = "ssh -t web13 'cd /data/var/www/vhosts/my.bytefreaks.net/htdocs/symfony/var/logs/; ls -la; bash'"
directory = ""
order = 1
parent = child17
profile = default
title = MA Live logs
type = Terminal
uuid = cb7d737c-a064-4e0e-ad5e-59c47d7bdd3b
[[[terminal2]]]
command = cd /vhosts/www.bytefreaks.net/; git pull; bash
order = 0
parent = child1
profile = default
title = www.bytefreaks.net
type = Terminal
uuid = d3c317d7-964a-4625-96d0-39deb5166072
[[[terminal3]]]
command = cd /vhosts/my.bytefreaks.net/; git pull; bash
order = 1
parent = child1
profile = default
title = my.bytefreaks.net
type = Terminal
uuid = 93ce7874-059e-4794-b337-7b640654a3d6
[[[terminal6]]]
command = cd /vhosts/www.michanicos.com/; git pull; bash
order = 0
parent = child5
profile = default
title = www.michanicos.com
type = Terminal
uuid = 2f204209-0c0b-4fab-b883-95f95f5d38e9
[[[terminal7]]]
command = cd /vhosts/www.etea.com.cy/; git pull; bash
order = 1
parent = child5
profile = default
title = www.etea.com.cy
type = Terminal
uuid = 6f801914-5225-4e1f-b54c-f48540274614
[[[terminal9]]]
command = cd /vhosts/www.ieee.org/; git pull; bash
order = 0
parent = child8
profile = default
title = www.ieee.org
type = Terminal
uuid = 3dbfe3a7-2e25-4e7d-bb02-dc4aeeeda47f
[plugins]
[profiles]
[[default]]
background_darkness = 0.8
cursor_color = "#ffffff"
foreground_color = "#ffffff"
