How to make base64 print the encoded output after a newline without newline being encoded? I like to encode with base64 from stdin by invoking the command pasting the input and pressing Ctrl + D twice in order to avoid a trailing newline if I don’t want one to be part of the input. It …
How to pass the standard input of a shell script to a background command In a shell script, I am trying to start a background command that has the same stdin as that of the shell script. #!/bin/sh # … the-program & However, the-program above will not have access to the same standard input as …
Why is stdin input replacing or corrupting my variables when running a script using SSH? GNU bash, version 4.3.27 I’m running into an odd issue with a script that writes output to a file. The script ssh’s to a list of servers and records the state/substate of a few services. I then store the results …
When and where are the standard in, out, and error file descriptors first opened in linux? Where are stdin, stdout, and stderr (the fds) first opened? Is it the kernel that does it? And when and where are the symlinks /dev/std{in,out,err} made? Where is the code that does it? I assume it is in the …
Calling vim in subprocess after running cat I am trying to create a bash function vim_run which operates as follows: user pipes command output into vim_run user can edit output user exits vim and the contents of that buffer are now executed via source file This flow is useful for editing a list of files …
Stop stdin while command is running How to stop stdin while command is running in ash (not bash)? For example: sleep 10 type echo hello while sleep is still running observe hello is in stdout after sleep finishes Desired: sleep 10 type echo hello while sleep is still running observe shell as if nothing was …
Processing a continuous single line of data with stream processing in bash pipeline? I am debugging an embedded server that outputs a continuous single line of text to a specified network port. There is no newline anywhere in the stream but it is text data and I would like to format it as it outputs. …
How to redirect a command's `stdin` as well as `stdout` to the output Suppose I have the Python script: #!/usr/bin/env python input(‘Y/n: ‘) print(‘Next line’) After I press Y, I want both the terminal and my output.txt containing: Y/n: Y Next line Running the following I don’t get Y in the output: $ python ask.py …
KeepassXC-cli: Send password to stdout I would like to authenticate to neomutt using keepassxc. I could not find a way to send password to neomutt’s stdin. How can i do that ? I imagine something like this: keepassxc-cli exportpass mydatabase.kdbx mymail@gmail.com end output would be the password it self. How can I achieve this ? …
Bash bind command does not work correctly for interactive commands When I try bind some commands with bind -x bash utility, I can’t see my stdin input on terminal. Example: root> # bind -x ‘”C-p”: su dargod’ When I type ctrl+P – I login to user dargod, but all what I types not shows. Same …
Portable way to invoke tar with a list of files from stdin I want to create a .tgz from the content of a directory. I also want to strip the leading “./” from the tar’ed content. I had done this as follows: cd /path/to/files/ && find . -type f | cut -c 3- | xargs …
Why does libarchive's bsdtar's unzip throw away the permission bits when reading a ZIP-archive from stdin, but not directly? I encountered that the command bsdtar from the package libarchive (under Arch Linux, at least) does throw away executable bits of files in .zip-archives when reading from stdin, but not when directly working on the file. …
How to check if stdin is /dev/null from the shell? On Linux, is there a way for a shell script to check if its standard input is redirected from the null device (1, 3) *, ideally without reading anything? The expected behavior would be: ./checkstdinnull -> no ./checkstdinnull < /dev/null -> yes echo -n | …
How does `cat`'s I/O model differ from that of other utilities? From the output of stdbuf –help (GNU): Usage: stdbuf OPTION… COMMAND Run COMMAND, with modified buffering operations for its standard streams. … NOTE: If COMMAND adjusts the buffering of its standard streams (‘tee’ does for example) then that will override corresponding changes by ‘stdbuf’. …
Make tar from /dev/stdin file What I’m looking for is a way to pass in arbitrary data through STDIN, and have it get tar’d up as if its a normal file. I tried this $ echo test | tar -cf test.tar /dev/stdin and that gives me a test.tar file with the contents dev/stdin. The stdin …
Problems caused by STDIN set to non-blocking mode Certain commands start to consistently fail in a given terminal window: $ sudo apt-get install ipython … After this operation, 3,826 kB of additional disk space will be used. Do you want to continue? [Y/n] Abort. $ $ kinit -f <username> Password for <username>@<domain>: kinit: Pre-authentication failed: …
Communicate backwards in a pipe I have a simple pipeline: node foo.js | node bar.js bar.js will read from stdin to get data from foo.js. But what I want to do is ensure that bar.js gets one of the last messages from foo.js before foo.js decides it’s OK to exit. Essentially I want to create …
echo or print /dev/stdin /dev/stdout /dev/stderr I want to print the value of /dev/stdin, /dev/stdout and /dev/stderr. Here is my simple script : #!/bin/bash echo your stdin is : $(</dev/stdin) echo your stdout is : $(</dev/stdout) echo your stderr is : $(</dev/stderr) i use the following pipes : [root@localhost home]# ls | ./myscript.sh [root@localhost home]# …
SSH connections running in the background don't exit if multiple connections have been started by the same shell Apparently, if the same shell launches multiple ssh connections to the same server, they won’t return after executing the command they’re given but will hang (Stopped (tty input)) for ever. To illustrate: #!/bin/bash ssh localhost sleep 2 …
How does bash file redirection to standard in differ from shell (`sh`) on Linux? I wrote a script which switches users while running, and executed it using file redirection to standard in. So user-switch.sh is… #!/bin/bash whoami sudo su -l root whoami And running it with bash gives me the behavior I expect $ bash …
