Any ideas why the which command is unable to find the usermod command in rhel 7. Here is what I did (and corresponding output) [ec2-user@ip-10-0-4-109 ~]$ echo $PATH /usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/ec2-user/.local/bin:/home/ec2-user/bin [ec2-user@ip-10-0-4-109 ~]$ which usermod /usr/bin/which: no usermod in (/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/home/ec2-user/.local/bin:/home/ec2-user/bin) [ec2-user@ip-10-0-4-109 ~]$ sudo su [root@ip-10-0-4-109 ec2-user]# which usermod /sbin/usermod [root@ip-10-0-4-109 ec2-user]# readlink -f /sbin/ /usr/sbin So the gist of the issue is that usermod is physically located in /usr/sbin/usermod. This directory /usr/sbin is in ec2-user search path. But for some reason which command is not returning it when I run it as ec2-user. Any ideas why this is happening on RHEL 7? I also have Ubuntu 14.04 and it works as expected (both root and regular user can see usermod in /usr/sbin). After initial post here is what else I found out: +++++++++++++++++++++++++++++++++++++++++ I found some addition information and I think this may have something to do with this: On RHEL 7 the permission bits for usermod -rwxr-x---. 1 root root 113800 Jun 28 2016 /usr/sbin/usermod On Ubuntu 14.04 the permission bits for usermod -rwxr-xr-x 1 root root 110296 May 16 19:37 /usr/sbin/usermod So I am guessing not having read permission for regular user on usermod maybe causing this?

When looking for the path to an executable or checking what would happen if you enter a command name in a Unix shell, there's a plethora of different utilities (which, type, command, whence, where, whereis, whatis, hash, etc). We often hear that which should be avoided. Why? What should we use instead?

$ xdg-open The program 'xdg-open' is currently not installed. You can install it by typing: sudo apt-get install xdg-utils $ sudo apt-get install xdg-utils Reading package lists... Done Building dependency tree Reading state information... Done xdg-utils is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 89 not upgraded. $ whereis xdg-open xdg-open: /usr/bin/xdg-open /usr/bin/X11/xdg-open /usr/share/man/man1/xdg-open.1.gz $ which xdg-open $ xdg-open The program 'xdg-open' is currently not installed. You can install it by typing: sudo apt-get install xdg-utils No, I didn't mean "recursion". I'm on Linux Mint 15 MATE, but instead of MATE I'm using the i3 window manager. **Edit taking @slm's advice** $ type -a xdg-open type: xdg-open not found But it's in /usr/bin/xdg-open. I checked. $ dpkg -S /usr/bin/xdg-open xdg-utils: /usr/bin/xdg-open The next one was even more interesting. $ dpkg -S xdg-open git-annex: /usr/share/doc/git-annex/html/bugs/Fix_for_opening_a_browser_on_a_mac___40__or_xdg-open_on_linux__47__bsd__63____41__.html xdg-utils: /usr/bin/xdg-open xdg-utils: /usr/share/man/man1/xdg-open.1.gz The bug-fix is just a mail archive of a patch for an OSX problem. Anyway, I guess I could try using the full path: $ /usr/bin/xdg-open /usr/bin/xdg-open: No such file or directory

When I run which node the command works, but if I run su - username -s /bin/bash -c 'which node' it returns empty. I have tried everything under the sun and can not get it to work. I even tried su - username -s /bin/bash -c 'source ~/.bashrc ; which node'

-shellsession
root@vps-151c25b9:~# which node
/root/.nvm/versions/node/v20.18.0/bin/node
root@vps-151c25b9:~# su - username -s /bin/bash -c 'which node'
root@vps-151c25b9:~#
root@vps-151c25b9:~# su - username -s /bin/bash
username@vps-151c25b9:~$ which node
/home/username/.nvm/versions/node/v20.18.0/bin/node
username@vps-151c25b9:~$

What am I doing wrong? Why doesn't node show up when run with su ? **Edit:** I just noticed, when I run

-sh
su - username -s /bin/bash -c "echo $PATH"

I get the path of root, not of the user *username*. Although root also has nvm & node and it doesn't find that either. **Edit 2:** I tried single quotes , so it doesn't expand $PATH and got my correct path including nvm dir:

-sh
su username -c 'echo $PATH'

but when I try

-sh
su username -c 'source ~/.bashrc ; which node'

it still is empty. **Edit 3:** I tried

-sh
su username -c '. ~/.profile ; which which'

(lol) and it returned

/usr/bin/which

, so the command works, just not for node. **Answer:** I ran the following and it worked! I had to load NVM manually.

-shellsession
root@vps-151c25b9:~# su - username -c 'export NVM_DIR="$([ -z "${XDG_CONFIG_HOME-}" ] && printf %s "${HOME}/.nvm" || printf %s "${XDG_CONFIG_HOME}/nvm")" ; [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" ; which node'
/home/username/.nvm/versions/node/v20.18.0/bin/node

Thank you everyone for your help :)

For a shell script I need to call an executable by name, regardless of the path leading there; thus far I know this code reports the right name:

tmpprog=which program
prog=${tmpprog%%*/}
if $prog=""
then
  echo >&2 "Main Program not found"
else
  echo >&2 "$prog"
fi

How can I cut the code so that I may trim the path to keep the executable name and remove the path in a one liner? Beware: basename won't do it, since I may be working on a hybrid environment (cygwin/busybox on windoze), and sometimes the paths have spaces.

I am reading the [source code of the Maven wrapper written for the Bourne shell](https://github.com/apache/maven-wrapper/blob/102d7b50cd756b0ac922ef07378c1fe3c9686473/maven-wrapper-distribution/src/resources/mvnw#L103) . I came across these lines:

if [ -z "$JAVA_HOME" ]; then
    javaExecutable="$(which javac)"
    if [ -n "$javaExecutable" ] && ! [ "$(expr "$javaExecutable" : '\([^ ]*\)')" = "no" ]; then
# snip

expr when used with arg1 and arg2 and a : matches arg1 against the regex arg2. Normally, the result would be the amount of matching characters, e.g.:

$ expr foobar : foo
3

However, when using capturing parentheses (\( and \)), it returns the content of the first capturing parentheses:

$ expr foobar : '\(foo\)'
foo

So far, so good. If I evaluate the expression from the source quoted above on my machine, I get:

$ javaExecutable=$(which javac)
$ expr "$javaExecutable" : '\([^ ]*\)'
/usr/bin/javac

For a non-existing executable:

$ nonExistingExecutable=$(which sjdkfjkdsjfs)
$ expr "$nonExistingExecutable" : '\([^ ]*\)'

Which means that for a non-existing executable the output is a empty string with newline. What's puzzling me in the source is how the output of which javac (arg1 to expr) ever returns the string no? Is there some version of which which, instead of returning nothing, returns no when no executable can be found? If not, this statement always evaluates to true and that would be weird.

I am looking for a script that would tell me what exactly installed a binary (or other asset) on a (Debianish) Linux system. Nowadays there are so many package managers (snap, flatpak, pip, npm, composer, conda, brew, clib, cargo) besides apt*/rpm/manual that its a real hassle to find out what exactly installed what and more importantly: what package manager is supposed to keep it up to date. ### Use cases - These days its vital to distinguish between an app installed by the apt mechanism and something installed by snap - When installing an app, one would prefer to find out if and what installed it before.

What is the difference between where and which shell commands? Here are some examples ~ where cc /usr/bin/cc /usr/bin/cc ~ which cc /usr/bin/cc and ~ which which which='alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde' /usr/bin/which ~ which where /usr/bin/which: no where in (/usr/local/bin:/bin:/usr/bin:/home/bnikhil/bin:/bin) also ~ where which which: aliased to alias | /usr/bin/which --tty-only --read-alias --show-dot --show-tilde which: shell built-in command /usr/bin/which /usr/bin/which ~ where where where: shell built-in command To me it seems that they do the same thing one being a shell builtin, not quite sure how that is different from a command?

My company has multiple servers that were setup to be identical. After using dev32 for several weeks, which stopped functioning. I go to dev35 and get similar behavior -- works for several weeks then one day it stops. dev36 is ok for now, but following this pattern I'll eventually run out of systems to use. Any thoughts on what could be causing this behavior?

dev32 ~> which python3
python3: Command not found.
dev35 ~> which python3
python3: Command not found.
dev36 ~> which python3
/bin/python3

dev32 ~> ls -al /bin/python*
lrwxrwxrwx. 1 root root     9 Jan 17 10:18 /bin/python3 -> python3.6
-rwxr-x---. 2 root root 11328 Nov 16  2020 /bin/python3.6
-rwxr-x---. 2 root root 11328 Nov 16  2020 /bin/python3.6m
dev32 ~> echo $PATH
.:/bin:/sbin:/usr/bin:/usr/bin/X11:/usr/bsd:/usr/sbin:/home//bin:/usr/local/bin:/usr/local/etc:/usr/local/sbin:/etc:/usr/etc:/usr/gnu/bin

dev35 ~> ls -al /bin/python3*
lrwxrwxrwx. 1 root root     9 Jan 17 10:11 /bin/python3 -> python3.6
-rwxr-x---. 2 root root 11328 Nov 16  2020 /bin/python3.6
-rwxr-x---. 2 root root 11328 Nov 16  2020 /bin/python3.6m
dev35 ~> echo $PATH
.:/bin:/sbin:/usr/bin:/usr/bin/X11:/usr/bsd:/usr/sbin:/home//bin:/usr/local/bin:/usr/local/etc:/usr/local/sbin:/etc:/usr/etc:/usr/gnu/bin

dev36 ~> ls -al /bin/python*
lrwxrwxrwx. 1 root root     9 Jan 17 10:18 /bin/python3 -> python3.6
-rwxr-x---. 3 root root 11328 Nov 16  2020 /bin/python3.6
-rwxr-x---. 2 root root 11328 Nov 16  2020 /bin/python3.6m
dev36 ~> echo $PATH
.:/bin:/sbin:/usr/bin:/usr/bin/X11:/usr/bsd:/usr/sbin:/home//bin:/usr/local/bin:/usr/local/etc:/usr/local/sbin:/etc:/usr/etc:/usr/gnu/bin

Even after cd /bin, which cannot find python3 Other knowns: - All servers are CentOS 7.9, uname -a matches - Ran rpm -qa | sort > $HOSTNAME.txt on each server and compared. results are identical - bash v4.2.26, tcsh v6.18.01 (same across all systems) - Behavior confirmed by multiple users; tcsh & bash yield same results. One user's shell uses system defaults (no ~/.bashrc, ~/.tcshrc or ~/.login), I customize mine. - IT says they haven't changed anything beyond standard monthly patching that is applied consistently to all servers. - Problem persists across reboots Please let me know if more information is needed.

I can't recall that command and I can't even find it in Google. It's just killing me. The usage of the command is like: which bash The output looks like: /etc/skel/.bash_logout /etc/skel/.bash_profile /etc/skel/.bashrc Took bush just for example of course. It may be any command. Upd: I use the Redhat based OS.

We are running: Red Hat Enterprise Linux release 8.5 (Ootpa). We allow the server to update weekly using "yum -y update". We recently began receiving the following errors when executing shell commands: - sh: which: line 1: syntax error: unexpected end of file - sh: error importing function definition for `which' I am not aware of anything we changed that could cause this error -- this why I am pointing to the yum system update. Much of our code is written in php where we use passthru() to run shell commands. When we rarely write a shell script we generally use bash. I have the ability to prevent these errors using "unset which" prior to running a php script that uses passthru(). We run many shell commands from many scripts. Updating each of these scripts is not an effective solution -- time consuming and potentially introduces defects. It is interesting to note that the following code Does Not cause an error:

#!/bin/sh
echo hello

Is there a way to 'unset which' once at the system or user level so it would be executed each time we run the shell? Perhaps there is a shell profile that I can change or something similar. **Update 1** I found the following in /etc/profile.d/which2.sh

# shellcheck shell=sh
# Initialization script for bash, sh, mksh and ksh

which_declare="declare -f"
which_opt="-f"
which_shell="$(cat /proc/$$/comm)"

if [ "$which_shell" = "ksh" ] || [ "$which_shell" = "mksh" ] || [ "$which_shell" = "zsh" ] ; then
  which_declare="typeset -f"
  which_opt=""
fi
 
which ()
{
(alias; eval ${which_declare}) | /usr/bin/which --tty-only --read-alias --read-functions --show-tilde --show-dot "$@"
}

export which_declare
export ${which_opt} which

The syntax looks correct here. I can tell that it exports 'which' -- but I'm not sure why. If I knew what this is doing, I could evaluate the risk of

which

. **Update 2** Created a small php script:

#!/usr/bin/php

This Does create the error.

I uninstalled nodejs the other day and now for some reason when I access it I get the error that node is not found. The argument of the which command can be anything.

> which wget                                                                                                                                                                        
/usr/bin/env: «node»: No such file or directory

However, if I install the node again, everything is fine:

> sudo pacman -S nodejs
...

> which wget                                                                                                                                                              
/usr/bin/wget

I've made a fresh install of Debian Wheezy, and installed zsh to it. Few days after, I've done a vanilla installation of TeX Live 2014, so I added the necessary binary paths to my $PATH. Now I started writing little scripts so I would like to put them somewhere easily accessible, that is ~/bin. My path looks like this: ~/bin:/opt/texbin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games Now, if I wanted to run something from TeX Live, it's easy: % which pdflatex /opt/texbin/pdflatex No problem. But when I try running something from ~/bin, ... % which hello_world hello_world not found So I double-checked: % ls -l ~/bin total 18 -rwxr-xr-x 1 bozbalci bozbalci 5382 Sep 8 00:28 hello_world And it shows that hello_world is doing fine in ~/bin with its execution permissions set. I've tried rehash, but it didn't work. Help?

I would like to use the result of which ls and see the file type using file. However, when I type in which ls | file it doesn't work. When I try to do file < which ls, that doesn't work either. Any pointers would be appreciated.

I have recently installed the

. I've double checked with

apt-get install cryptsetup

.

Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
cryptsetup is already the newest version (2:2.3.7-1+deb11u1).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

However when I try to use the command it does not recognize it.

bash: cryptsetup: command not found

Then I tried to find the location of the command using

.

cryptsetup

However the command does not return anything.

cryptsetup

says that

indeed is the right command name. What is wrong here?

I am trying to locate which conda executable I am using. For this, I want to use which command. As per man pages, it should return the path of the executable. Instead it returns some bash function (base) ➜ ~ which conda conda () { \local cmd="${1-__missing__}" case "$cmd" in (activate | deactivate) __conda_activate "$@" ;; (install | update | upgrade | remove | uninstall) __conda_exe "$@" || \return __conda_reactivate ;; (*) __conda_exe "$@" ;; esac } If I try to see the location of __conda_exe, again I get another function: __conda_exe () { ( __add_sys_prefix_to_path "$CONDA_EXE" $_CE_M $_CE_CONDA "$@" ) } where is the conda function I am using?

Does anyone know where to begin with debugging this? [chuck@vmlnx-tacx32 openssl-1.1.0h]$ which -a python /usr/local/bin/python /usr/bin/python [chuck@vmlnx-tacx32 openssl-1.1.0h]$ /usr/local/bin/python Python 3.7.6 (default, Feb 23 2022, 13:10:48) [GCC 4.4.7 20120313 (Red Hat 4.4.7-23)] on linux Type "help", "copyright", "credits" or "license" for more information. >>> exit() [chuck@vmlnx-tacx32 openssl-1.1.0h]$ python Python 2.6.6 (r266:84292, Jul 23 2015, 14:41:34) [GCC 4.4.7 20120313 (Red Hat 4.4.7-11)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> exit()

I have this command that I run. Let's call it foo. I can execute foo without specify the full path to foo like so:

$ foo
missing args

I suspect foo is a bash script so I want to look at the source code in foo, but when I do which foo I get the standard error message:

which: no foo in (/usr/local/bin ...removed for brevity ...)

What gives?

In bash I see which returns the paths in order, but in zsh it has different ordering. I now primarily use zsh, how can I get proper output ordering of which in zsh? Why is it different? I expected the ordering to match my path. My path is: /usr/local/bin:/usr/bin

bash$ which -a git
/usr/local/bin/git
/usr/bin/git

zsh$ which -a git
/usr/bin/git
/usr/local/bin/git -> ../Cellar/git/2.32.0/bin/git

I read https://unix.stackexchange.com/questions/9683/which-but-all/ but I cannot really get the difference. I am running zsh 5.4.2 on 64-bit debian-buster. Both which and whence are shell-builtins . Can people point out where whence would be more appropriate than which and vice-versa ? /home/shirish> zsh --version zsh 5.4.2 (x86_64-debian-linux-gnu) /home/shirish> type -a which which is a shell builtin which is /usr/bin/which which is /bin/which /home/shirish> type -a whence whence is a shell builtin