I have defined a few key bindings for gnuplot in a file key-bindings.gp which I can have available by launching gnuplot with
gnuplot key-bindings.gp -
However, if I do this, then gnuplot does not load the command history; it is just empty. (NB: I guess it makes sense in the way that specifying a script with gnuplot-commands on the command line is intended for batch processing rather than an interactive session.)
On the other hand, I also would not like to have these key bindings in my central ~/.gnuplot file but I want to have them available only in certain situations.
Is there a way to load these key bindings on start-up, i.e. to define different gnuplot environments without losing access to my command history?
One way would be to do load 'key-bindings.gp' once I've started gnuplot but I don't like this because I want to automate some gnuplot processes and I also don't know how to automatically write this command onto the gnuplot command line...
Using environmental variables
[1] cat ~/.gnuplotrc
env1 = system("echo $MY_KEYS")
if (env1 ne "") load env1
env2 = system("echo $MY_STYLES")
if (env2 ne "") load env2
[2] setenv MY_KEYS key-bindings.gp
[3] setenv MY_STYLES pref-styles.gp
[4] gnuplot
gnuplot> print env1
key-bindings.gp
gnuplot> history !print
Executing:
print env1
foo.gp
Related
Docker env files look similar to shell scripts defining variables.
Unfortunately in env files, values cannot be quoted and so simply sourcing them only works if there are no "special" characters in the values.
VAR1=This_works
VAR2=This will not work
VAR3=This won't either
Is there any way you can use these files in a shell script?
My current approach is this:
eval $( perl -ne '
s/\x27/\x27\\\x27\x27/g;
s/^(\w+)=(.+)$/export $1=\x27$2\x27/ and print
' "path/to/env_file" )
So I'm searching for any quote in each line of the env file and replace it by '\''.
Then I'm modifying each line which starts with an identifier (\w+) followed by a = and any text (.+). So the VAR3 will become: export VAR3='This won'\''t either.
The modified line is then printed.
Everything which was printed is eval-ed and so the variables will be available in my shell's environment.
Are there other proposals how to achieve this?
I am trying to use env variables in my rails app and set those variable values in ubuntu 14.04
I tried setting using export command
export mongodb_username="abc"
export mongodb_password="cde"
and also tried setting them in /etc/environment and in ~/.bashsrc
and printenv gives following results
>> printenv mongodb_username
=> abc
>> printenv mongodb_password
=> cde
BUT in RAILS APP or irb the output is following
>> ENV['mongodb_password']
=> nil
>> ENV['mongodb_username']
=> nil
I am missing something? Please help!!!
When setting an environment variable's value using export, that value is available only in the shell in which it was set, and its subshells. So you'll need to export those variables in every shell in which you need them.
However, you can automate this, of course.
If you have variables that you need frequently, one approach is to put their assignments in a shell script and then source the shell script in any shells you need them in (see http://www.tldp.org/HOWTO/Bash-Prompt-HOWTO/x237.html for more on this).
If it's ok to have the variables be in effect in all your shells, then a simpler way is to export them from your startup script (probably ~/.bashrc).
I need to change multiple u-boot environment variables every time I setup a new embedded device e.g. ip address, ethernet address, etc.
Typing at the terminal prompt is tedious, and, I don't know if it's my terminal, buy trying to cut and paste anything more than a few characters can result in errors. Changing them in a text editor and copying that file to a specific location in flash would be much better than the terminal.
Anyone have a good way to change multiple environment variables at once?
A script file is ideal for this situation. Its much better than copy & pasting for many commands and can handle much more complexity. You can enter all your commands into a text file and create a script image using mkimage (where myscript is the text file's name):
mkimage -T script -C none -n 'My Script' -d myscript myscript.img
Then you can simply load and execute myscript.img to perform all setup tasks for the device.
For example, to load and execute myscript.img from USB stick:
usb start && load usb 0:1 ${loadaddr} myscript.img && source ${loadaddr}
It is possible to add this load command to U-Boot's default environment so all you need to do is run the name of the command. You can even add logic to the default boot sequence to automatically perform the device setup if the USB device and script file are present. Depending on the U-Boot version, you can manipulate the default environment by either modifying the U-Boot source or by editing uEnv.txt (when supported).
Scripts are also useful for maintaining multiple setup configurations that would allow you to set the device up for one of many deployment or development configurations.
I have been able to use PuTTY to copy and paste my variables into U-Boot. You can separate the declarations by semicolons to if you want to do all of the variables at once, like this:
setenv ipaddr 192.168.1.5; setenv serverip 192.168.1.10;
I have a little script to read my PATH and store in a file, which I would like to be scheduled to run daily.
path = os.getenv("PATH")
file_name = "C:\\temp.txt"
file = io.open(file_name, "w")
file:write(path)
file:close()
If I run it from command line it works, but when I create batch file (I work on Windows XP) and double click it - the os.getenv("PATH") returns false. The batch file:
"C:\Program Files\Lua\5.1\lua" store_path.lua
I read in comments to this question that it "is not a process environment variable, it's provided by the shell, so it won't work". And indeed, some other env variables (like username) work fine.
The two questions I have are:
Why the shell does not have access to the PATH? I thought it would
make a copy of the environment (so only setting env variable would be a problem)?
What would be the best way to read the PATH in such a way that I can add
it to a scheduler?
Have the batch file run it from a shell so that you get shell variables:
cmd /c C:\path\to\lua myfile.lua
I would like to inherit environment variables in GNU Parallel. I have several 'scripts' (really just lists of commands, designed for use with GNU Parallel) with hundreds of lines each that all call different external programs. However, these external program (out of my control) requires that several environment variables be set before they will even run.
Setting/exporting them locally doesn't seem to help, and I don't see any way to add this information to a profile.
The documentation doesn't seem to have anything this, and similar SO pages suggest wrapping the command in a script. However, this seems like an inelegant solution. Is there a way to export the current environment, or perhaps specify the required variables in a script?
Thanks!
This works for me:
FOO="My brother's 12\" records"
export FOO
parallel echo 'FOO is "$FOO" Process id $$ Argument' ::: 1 2 3
To make it work for remote connections (through ssh) you need to quote the variable for shell expansion. parallel --shellquote can help you do that:
parallel -S server export FOO=$(parallel --shellquote ::: "$FOO")\;echo 'FOO is "$FOO" Process id $$ Argument' ::: 1 2 3
If that does not solve your issue, please consider showing an example that does not work.
-- Edit --
Look at --env introduced in version 20121022
-- Edit --
Look at env_parallel introduced in 20160322.