A set of dynamic variables that can affect the running processes.

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2
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1answer
680 views

Bash script for running python virtual environment does not execute

I am trying to wrap the following call into a script, which runs my Python virtual environment: [lucas@lucas-ThinkPad-W520]/home/lucas/bin$ source ...
1
vote
0answers
41 views

Programmatically obtain LILYPOND_DATADIR for execlp() call

I wrote an application that calls lilypond by execlp()ing it. However, when my app executes this line, the following error occurs: GNU LilyPond 2.16.2 warning: not relocating, no 2.16.2/ or current/ ...
1
vote
1answer
207 views

Multiple MODULEPATH entries in .modulesbeginenv

I'm switching between paths/code projects. At each place I have different modules. To handle this there is a setup script that modifies what to use. This is handled with the tool 'module'. NOTE: ...
7
votes
1answer
11k views

how to set environment variables from a shell script? [duplicate]

I'm trying to set environment variable through a shell script. Here is the script with various techniques: #!/bin/sh echo "export SOMEPATH=/root/some" >> /root/.bash_profile echo "export ...
6
votes
2answers
526 views

if statement in .bashrc not working correctly

I set up .bashrc to show a long prompt if the terminal is at least 80 characters wide. Otherwise it shows a degraded, smaller prompt. I use an if statement to achieve this: dp_smaller_than=80 if [ ...
5
votes
3answers
377 views

Is there any harm in using variables that aren't set?

Say I have the following code: # Check if the color prompt is enabled and supported on this system if [ -n "$force_color_prompt" ] && [ -x /usr/bin/tput ] && tput setaf 1 ...
2
votes
1answer
52 views
1
vote
2answers
10k views

Setting PATH vs. exporting PATH in ~/.bash_profile [duplicate]

What's the difference and which is better to use when customizing my bash profile? Documentation on the export command is scarce, as it's a builtin cmd. Excerpt from version 1 of my ~/.bash_profile: ...
4
votes
2answers
545 views

How to guarantee availability of $BASH_ENV

A non-interactive, non-login shell will try to source any script specified in $BASH_ENV. But how do I guarantee $BASH_ENV is set before a cron job or script has a chance to set $BASH_ENV for any ...
5
votes
2answers
2k views

How can I expose JAVA_HOME to applications running under X and/or Gnome?

I'm trying to run IntelliJ from Gnome3's Applications menu, but it complains the JAVA_HOME variable is not set. I have the Java installation under my home folder. I managed to export the variable in ...
5
votes
1answer
111 views

What else can break if I remove export from a variable?

My problem is that when I started coding my script I encountered several variable scope issues which resulted in the bad habit of exporting almost all my variables. Now that my code has got quite ...
2
votes
0answers
52 views

Why does xdg-open text_file differ from sudo -u me xdg-open text_file?

If I run the following command, the text file opens in my preferred editor (kate). $ xdg-open text_file However, if I try the following, where sparhawk is my username, I get several warnings, and ...
3
votes
4answers
211 views

Protected environment variables?

Are there names of environment variables that cannot be overwritten by the user/a call to setenv? As I understand from POSIX1.2008, any process may edit the environment block, but must avoid ...
3
votes
1answer
529 views

Why can I only use apt-get when I use “su”?

Not sure what info you need here, if any. Just let me know. I have a proxy that bypasses the corporate net set in my profile file for both su and normal user. When I do a sudo or regular apt-get ...
4
votes
1answer
12k views

how to make PKG_CONFIG_PATH variable to refer an installed library?

I am in the process of installing the required libraries for FireFox 3.6 on a Redhat Linux Nash 4.x system. I already have successfully installed the glib2.12.0 library, but When I ./configure the ...
1
vote
2answers
2k views

How do I get a variable's value from one script and import it in another script?

How do I get a variable's value from one script and import it in another script? But the catch is that the script where I am going to get the variable's value has also some commands that I don't want ...
5
votes
3answers
536 views

Environment variables are not set when my function is called in a pipeline

I have the following recursive function to set environment variables: function par_set { PAR=$1 VAL=$2 if [ "" != "$1" ] then export ${PAR}=${VAL} echo ${PAR}=${VAL} shift ...
1
vote
4answers
965 views

chmod - change permissions on a file

I have a Python virtualenv, and the Python executable is located in the /bin directory. In this virtualenv I'll have to execute some unsafe code, that can damage my system. I tried to chmod a-r on the ...
1
vote
1answer
42 views

Sourcing scripts with a for loop for different variables

I have several shell scripts that I summarised within a global script. I am using some variables that are the same across all scripts, and I wrote a separate script for this, which I am sourcing in ...
5
votes
7answers
2k views

how to share environment variables between shells like globals related to a master pid?

So, I need to share environment variables between shells, and that the changes on the variables be promptly recognized by all shells, like global variables. But they must be related to a master pid, ...
0
votes
1answer
84 views

Is there a command which displays options like `errexit` and `braceexpand` other than `help set`?

If you type help set, then - among other things - a list of shell options is displayed. But these options are not the same as those displayed with shopt. And different also from those displayed with ...
23
votes
3answers
2k views

If processes inherit the parent's environment, why do we need export?

I read here that the purpose of export in a shell is to make the variable available to sub-processes started from the shell. However, I have also read here and here that "Processes inherit their ...
8
votes
4answers
9k views

Prevent SSH client passing TERM environment variable to server?

I'm currently using Fedora 18 gnome-terminal, then started tmux multiplexer in it. After I connected to a CentOS 5 server via ssh command, I find: ls result has no color tmux, screen, hexedit, htop ...
1
vote
2answers
92 views

Toggle/macro/xargs-like thing for shell variables

So I'm stuck doing a lot of cross-compiling and am typing stuff like this a lot FOO=bar command --some-args BAZ=qxt other-command --other-args But obviously the real shell variables are long and ...
3
votes
1answer
197 views

Difference between “.” and “./” while setting the environment variables using export? [duplicate]

Please excuse me if I am not clear while asking questions. I will try my best to be very clear while asking questions. While learning Embedded Linux, we are setting an environment for our project. ...
24
votes
3answers
9k views

How to run a program in a clean environment in bash?

I want to run a program in an empty environment (i.e. with no envariables set). How to do this in bash?
0
votes
4answers
197 views

Unset http_proxy enviroment variable

Updated 11/03: After doing some test with your suggestions, I only can be sure about one thing: there is something related to the graphical environment, because if I login through ssh or using ...
2
votes
2answers
474 views

Variable value is not recognized after using gnu parallel?

I have a below shell script from which I am trying to copy 5 files in parallel. I am running my below shell script on machineA which tries to copy the file from machineB and machineC. If the file is ...
0
votes
3answers
999 views

TERM variable in chroot

I've created a chroot with the help of jailkit and now I'm trying to install some other libraries and tools. First I tried to install clear library. I've copied the file from the /bin folder and ...
1
vote
0answers
75 views

Create global enviromental variable after boot

I know about /etc/profile and /etc/environment, but I would like to set a global environmental variable after boot and login. By global, I mean an environment variable that can be accessed by any ...
3
votes
2answers
150 views

What environment and credential is used by startup, background and service processes

Startup scripts (on boot) Processes running in (or sent to) the background (when using SSH -fN for example) Services etc... What $path variable will they be using? What credentials? Anything else I ...
23
votes
5answers
3k views

why is setting a variable before a command legal in bash?

I've just encountered several answers such as to parsing a delimited text file... that use the construct: while IFS=, read xx yy zz;do echo $xx $yy $zz done < input_file where the IFS ...
17
votes
7answers
902 views

How do I source another process's environment variables?

If I examine /proc/1/environ I can see a null-byte-delimited string of process 1's environment variables. I'd like to bring these variables into my current environment. Is there an easy way to do ...
4
votes
1answer
2k views

System environment variables not appearing in sudo

I have the following line my /etc/environment file: BROKER_URL=tcp://xxx.30.8.163:61616 I run this and get: $ set|grep BROKER_URL BROKER_URL=tcp://xxx.30.8.163:61616 Then, I run: $ sudo bash # ...
3
votes
1answer
259 views

Set environment inside `nsenter /bin/bash`

I'm entering a namespace with nsenter -m -u -i -n -p -t $PID /bin/bash. However, printenv inside this namespace doesn't have everything I need. I'd like to send these variables in, but I'd like to ...
1
vote
0answers
94 views

Setting environment variables at runtime in KDE4

Is it possible to set an environment variable at runtime, affecting all the programs started from the DE after that point (Desktop Environment, in my case KDE4) (without rebooting)? I know it it ...
3
votes
2answers
290 views

184 environment variables too many?

I am trying to find the cause of some OS wonkiness, and am concerned about environment variables. The software I have been handed puts an incredibly high amount of environment variables into the ...
3
votes
1answer
703 views

Is the $HOME environment variable always set on a Linux system?

Assuming the machine is running a Linux kernel, sessions make use of the Bash shell and everything is using default configurations (no user has made any changes to config files), can we assume that ...
6
votes
3answers
575 views

Understanding environmental variables in different contexts

Trying to understand the behaviour of the environment in Linux (Ubuntu 13.04 concretely), I've find different situations where setting envirionment variables are used or defined for/in different ...
0
votes
2answers
123 views

How can I ensure that a custom environment variable is set before cron runs a task?

I recently experienced a logwatch issue that is fixed by running export DATE_MANIP=DM5. cron seems to forget this when I logout (presumably because it's not saved). Where can I add this custom ...
2
votes
4answers
2k views

bash script and local env variable namespace collision

I have a bash script with a variable called VAR_A I also have a local env variable called VAR_A The bash script calls the command: echo ${VAR_A} I am not able to change the variable in the script ...
1
vote
1answer
1k views

How can I set up environmental variables for www-data?

I asked a question on dba.se about how I can give my Perl CGI script the password it needs to access the MySQL database it needs to query. I have received only one answer but that one suggests I save ...
2
votes
3answers
627 views

setting environment variable as a function of another env variable [duplicate]

I would like to set an environment variable (that we'll call "TEST") to store the path to a sub-directory of my home directory : something like /home/myself/dir/. I would like to use the $HOME ...
2
votes
2answers
244 views

What does `env COLUMNS=%S ps …` do?

I have seen the syntax env COLUMNS=%sin shell scripts, e.g. see the line below from the Helm package in Emacs: env COLUMNS=%s ps -axo pid,user,pri,nice,ucomm,tty,start,vsz,%%cpu,%%mem,etime,command ...
4
votes
3answers
320 views

Why does export -p exclude $_ variable?

As far I know, there are 3 ways to see exported variables: $ export -p | wc -l 50 $ env | wc -l 51 $ printenv | wc -l 51 As you can see, export -p misses single variable. It's a $_ one: $ diff ...
1
vote
1answer
59 views

Who is setting http_proxy?

On an Ubuntu system with bash as the default shell for the interested user, the http_proxy environment variable is set to a specific value in a fresh GNOME Terminal. The .bashrc file for this user ...
0
votes
1answer
100 views

Permanent Environment Variable with # linux Ubuntu

I am trying to set some environment variables permanently by editing the /etc/environment file. One of my environment variables has a "#" in it and some text after the "#". Everything after the "#" ...
3
votes
2answers
2k views

Is there a way to push shell config information when SSHing to a host?

I know how to set the GNOME-terminals (or xterms!) prompt to green/red regarding the last exit code: vi .bashrc export PROMPT_COMMAND='PS1="` if [[ \$? = "0" ]]; then echo "\\[\\033[0;32m\\]"; else ...
6
votes
3answers
349 views

Is it possible to find out which files are setting/adding to environment variables, and their order of precedence?

Some of my environment variables ($PATH, $MANPATH and friends) are partially set up in different source files. I find myself wishing for a command or method to quickly gather what part, in a specific ...
3
votes
1answer
111 views

Where do I place commands to automatically be exported for all users?

I have an embedded platform running an Arago linux distribution. Right now the only "user" is root but there will eventually be others, but I don't know how many or what user IDs they will have. ...