Questions tagged [shell]
The shell is Unix's command-line interface. You can type commands in a shell interactively, or write scripts to automate tasks. Use this tag for questions applying to /bin/sh and most compatible shells (ash, bash, ksh, zsh, …). For shell scripts with errors, please check them in http://shellcheck.net before posting here.
1,157
questions with no upvoted or accepted answers
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Is it possible to send data to the the shell of another pseudo-terminal?
This image shows how pseudo-terminals work:
If I have two terminal emulators open, I can send the string "Hello" from the first terminal emulator to the second terminal emulator:
echo "Hello" > /...
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8
votes
1
answer
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List all jobs in all shell sessions (not just the current shell), by current user
I know that the jobs command only shows jobs running in current shell session.
Is there a bash code that will show jobs across shell sessions (for example, jobs from another terminal tab) for ...
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6
votes
1
answer
359
views
cp overrides my default permissions settings, when copying files with: cp -r --no-preserve=all
My default umask is 077. When I create a directory, it has permissions 700:
mkdir AA
$ stat -c'%A %n' AA/
drwx------ AA/
now I want to set default permissions recursively to 750:
...
- 333
5
votes
2
answers
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How to stop marking while in tmux copy-mode?
I want to mark and copy text, and then stay in copy-mode with the marker off, permitting me to move up/down without marking new text (see below).
But after marking text and pressing space or y to ...
- 3,789
5
votes
0
answers
199
views
Tracing environment variable modification in the fish shell
There's one item I used to use in $PATH, which is ~/.workspace/bin. I can't figure out where it's coming from.
I changed the user shell to /bin/sh, logged in from TTY, checked $PATH, and it was clear ...
- 245
5
votes
0
answers
827
views
Manually restore saved session files on KDE using qdbus command
At times, i have multiple konsole terminal open with multiple tabs. I would like to save and restore it manually, just in case i accidentally close the window. In KDE there is a command to save the ...
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5
votes
2
answers
287
views
Understanding fmt (gnu coreutils)
I'm using fmt (GNU coreutils) 8.25 and I fail to understand how to use it.
In particular, I don't understand the following results.
$ echo -n "a b c d e" | fmt -w3 -g3
I expected to obtain
a b
c d
...
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5
votes
1
answer
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Running scripts/commands from a host system in a chroot environment.
First of all, I have inside an android Operating System a chroot environment created using Linux Deploy. I am able to access it from Android using a terminal emulator and root permission. I would like ...
5
votes
1
answer
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Sending SIGINT to process groups sometimes gets ignored
I start a process group from bash. Then I send SIGINT to the entire process
group. Sometimes the SIGINT kills the processes, sometimes does not. Why does
SIGINT sometimes gets ignored ?
I see ...
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5
votes
1
answer
143
views
Is it possible to drop all write privileges in a shell for the current user
This is NOT for security purposes.
Suppose I wanted to execute a shell script and, on a best effort basis, assume it left no side effects aside from things like auditd logging, avc reports, syslog, ...
- 61
5
votes
0
answers
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convert windows path to unix path inside wine application command line
I'm running a windows application in wine, which executes configurable commands to run external applications (e.g. an diff editor to show differences between two source files). So these commands are ...
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4
votes
0
answers
156
views
Why does bash $LINENO change inside an inner block in a function?
I'm trying to debug auto completion script located in /usr/share/bash-completion/bash_completion (bash completion package on every distro)
I did
export PS4='+'$'\t''$LINENO'$'\t # \t for proper ...
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4
votes
0
answers
158
views
On MacOS, what character does `Esc+` or `+Esc` correspond to in Bash, when using iTerm2 terminal?
I've read that mapping Left Option key to Esc+ should fix many of the issues users of Bash, on MacOS, have with GNU Readline key-bindings.
However, I've never encountered Esc+ or +Esc before, so does ...
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4
votes
0
answers
305
views
Update all installed GNOME 3 extensions at once
I use extensions.gnome.org website and GNOME Shell integration Chrome extension to search and install gnome-shell extensions.
I know that I can use the website and the Chrome extension above to also ...
- 161
4
votes
2
answers
212
views
gunzip on Embedded machine
I'm using BusyBox 1.24.1 on my Embedded Linux machine (with kernel v3.10.31) and I get behavior I can't understand when unzipping files.
The gunzip command (often, but not always) fails,
with no ...
- 41
4
votes
0
answers
131
views
FreeBSD sh: is it possible to import a list of commands into fc without executing them?
I cannot find any indication that sh supports persistent history. So I am trying to create this functionality manually. At the end of my .shrc history I have added this:
trap -- 'fc -ln -- 1 >> ...
- 1,894
4
votes
0
answers
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Gain root access without using root's login shell
I bricked the login of my root user by removing zsh while it was still the default shell. Now as a result will login in fail, since on login will it try to use /bin/zsh(1), which is missing.
Only one ...
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4
votes
1
answer
4k
views
All TLS requests giving Peer's certificate issuer has been marked as not trusted by the user
When I try an https request to google.com, I just recently started seeing
[root@ip-172-31-47-76 ~]# curl -I -v https://google.com
* Rebuilt URL to: https://google.com/
* Trying 216.58.193.78...
* ...
- 41
4
votes
0
answers
189
views
Is there any utility that can drop me into a Intel ME Minix shell?
I see a lot of talk about Intel -3 ring mode running Minix. Is there any easy C program I can compile, or utility I can run that will drop me into a -3 ring mode Minix shell?
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4
votes
1
answer
435
views
Switching between two framebuffer programs
I have two programs (mplayer and a custom java application) which both present GUI using framebuffers. They run in separate processes. I want to be able to switch from one program to the other without ...
4
votes
1
answer
3k
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Run git pull from a shell start-up script
I have Raspberry Pi that loads a shell script on start up.
This script runs a python script, boot_camera.py, which is found in a repository.
I Have a server which sends the Raspberry Pi a command ...
- 41
4
votes
1
answer
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Run vsim from dmenu — it only works when directly invoked in the terminal
Works: vsim, sh -c vsim
Doesn't work: echo "vsim" | sh, echo "vsim" | xargs -I {} sh -c "{}"
I want to run ModelSim (vsim) with dmenu, which is triggered using xbindkeys.
Details
vsim is a ...
- 1,202
4
votes
1
answer
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set tab color in a tabbed terminal emulator
I would like to set in my terminal emulator (i.e. gnome-terminal) the color of the tabs like in the osx's terminal emulator. Is there this feature in any of the linux terminal emulator plethora?
EDIT:...
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3
votes
2
answers
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Why is git bash so slow to give me a command prompt and how can I fix it?
I used tcsh for decades on cygwin and just started using git-bash on my new Windows PC. It's generally a step up but the time from when the last command finishes until I receive the next command ...
- 141
3
votes
0
answers
321
views
Change zsh tab size
I wanted to change the tab size (the amount of spaces a tab uses) used in my terminal, but it didn't work.
I then found out, that my shell (zsh) inserts a fixed amount of 8 spaces instead of a tab.
I ...
- 121
3
votes
0
answers
216
views
What are profiling tools available for bash/shell script
I have a project which is entirely written in shell scripts.
I find some of the modules in my code takes a lot of time, I need to reduce it functionality wise.
What are profiling tools available for ...
- 183
3
votes
0
answers
77
views
force specific shell environment variable on process using /etc/pam.d/ rules
I am using slim login manager, and it has its own pam rules file: /etc/pam.d/slim.
auth requisite pam_nologin.so
auth required pam_env.so readenv=1
auth required pam_env....
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3
votes
1
answer
551
views
Can I run the command in specific terminal?
OS: Linux mint 19.2 Cinnamon
SHELL: Zsh
TERMINAL: Tilix
I want to create a shell script. which have 2 steps.
Open the new terminal.
Run source bin/activate at terminal that I opened.
How do I run ...
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3
votes
0
answers
311
views
How to write zsh completion function for wrapper commands
I'm attempting to write a completion function for a custom wrapper around SSH called myssh. myssh takes command line arguments in either of the following forms:
myssh [myssh options] [ssh args]
or
...
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3
votes
0
answers
44
views
Should I set the locale to `C` when matching a range of numbers?
If I wanted to search for lines in a file that contain a or b or c or d I would run
LC_COLLATE=C grep -E '[a-d]' file_to_search
or
LC_ALL=C grep -E '[a-d]' file_to_search
If I fail to set the ...
- 1,894
3
votes
0
answers
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Get/Set environment variables in a different tty
I'm using a tool (Autokey) that spawns in a new shell. Cool tool, but I want to pull info from my current shell.
Say I'm on pts/0 and I have a variable set: VAR1=yes. In another shell, I want to be ...
- 343
3
votes
0
answers
271
views
Source-able/executable shell script in the POSIX shell language
What's a good POSIX compliant way to make a script both executable (a function from the script gets executed) and in-sourcable with the . command (nothing happens except (at least) 1 function becomes ...
- 27.6k
3
votes
0
answers
858
views
Send response based on netcat client request
I am trying to create a socket where the client receives a response based on their request, but I can not figure out how to achieve this on CentOS 7.
Until now I have the socket opened on port 100 ...
3
votes
0
answers
360
views
Is there jitsi SIP-client for Ubuntu or Debian which has command-line interface?
Is there jitsi SIP-client for Ubuntu or Debian which has command-line interface? So, for example, I can make calls without using jitsi GUI, just sending commands to the application.
3
votes
0
answers
3k
views
Will a child process be in a different process group than the parent process?
I always thought that a child process will be in the same process group as the parent process. But I have read the following from here:
if you run some_app from the shell, the shell creates a new ...
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3
votes
0
answers
899
views
How can I send stdout to multiple commands in fish shell?
Same question as How can I send stdout to multiple commands? but for fish shell.
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3
votes
1
answer
481
views
Signal not received by script run using sh -c
I have a script which sleeps for 3 minutes before running a time consuming command. I want the script to exit if it receives SIGINT only while it is sleeping, and not when it is executing the long ...
- 207
3
votes
0
answers
485
views
Control characters in a terminal with an active foreground process
Say I have a process running in a terminal in the foreground. While it is active I can type commands, hit return, and those will be executed once the process is done.
Now say furthermore I would like ...
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3
votes
1
answer
127
views
New (login) shells (window) opens at $HOME rather than $PWD (like they used to) on macOS. What gives?
Every time I open a new shell window, I'm brought to my home directory rather than the current directory I was in when I gave the command to open a new Terminal.app window. I am under the impression ...
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3
votes
1
answer
106
views
zsh fail to keep unquoted `$*` and `$@` equal
All shells tested do the same for the (quoted) pair "$*" and "$@" with this code:
c='set a b @ c; IFS=:,@ ; a=$(printf "<%s> " "$*"); b=$(printf "<%s> " "$@"); printf "%-20s and %-20s\n" "...
user79743
3
votes
0
answers
831
views
Umask value isn't reflected after making changes
I changed umask from 002 to 007 in /etc/bashrc and in /etc/profile. After logging as a normal user I run umask, and it displays 0027. It should display 0007, but it doesn't. What should I do?
if [ $...
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3
votes
1
answer
72
views
Is there a version of the 'find' command that saves its state?
If a find is searching a large disc, and is aborted for some reason, I'd like to be able to start it again, from where it left off.
Is there a version of 'find' that does this?
The problem is that, ...
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3
votes
1
answer
687
views
"render" textfile with carriage returns (^M) and save output to file
I have a Python CLI program that runs for a long time and has a sort of progressbar, which basically prints some text in the loop without "\n" at the end, at the next iteration it prints "\r" to erase ...
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3
votes
1
answer
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How to kill inactive user logins on Solaris?
On a Solaris 10 server if i do a w, I get this:
12:26pm up 85 day(s), 1:13, 6 users, load average: 0.38, 0.36, 0.38
User tty login@ idle JCPU PCPU what
blah pts/1 ...
- 305
3
votes
1
answer
803
views
Secure share in samba not working, why?
The secure share that I created in samba with a password doesn't seem to work.
I have the following on my /etc/samba/smb.conf on a Linux Mint box(3.13.0-37-generic) box.
[myshare]
...
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3
votes
0
answers
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Where EOF character is processed when it sent over telnet connection
Let's suppose I am connecting to telnet server, where bash is running.
I am executing command cat > /tmp/qqq; typing some contents of a file and finally sending 0x0a 0x04 which meant EOF.
The ...
- 131
3
votes
1
answer
950
views
Generate SFV file, optimizing hard links
I'm currently running cfv -C -rr to generate a SFV file that contains the CRC32 checksums of all files in all subdirectories. The issue is that because there are so many hardlinks, this process is ...
- 31
3
votes
1
answer
819
views
Higher-level wrapper for entr or inotifywait
I'm looking for a way to rerun a specific command as soon as any of the files in a subdirectory (perhaps minus selected excludes) changes.
Use case
I'm working on a project that is self-contained in ...
- 917
3
votes
1
answer
2k
views
Read output in `screen` from outside
Suppose I opened up a screen to run some program that outouts some result.
Once the program finishes, is there a way to get the result in the screen from outside.
For example:
I opened up a screen ...
- 1,625
3
votes
1
answer
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nmap won't recognize a hostname on my local area network
Scanning the machine on the LAN with my laptop, I got this:
gabriele @ osiris { ~ } [ Tue Oct 07 ] [ 08:49 PM]
nmap -sP 192.168.1.236
Starting Nmap 6.40 ( http://nmap.org ) at 2014-10-07 20:50 CEST
...
