[linux] Bash script prints "Command Not Found" on empty lines

Every time I run a script using bash scriptname.sh from the command line in Debian, I get Command Not found and then the result of the script.

The script works but there is always a Command Not Found statement printed on screen for each empty line. Each blank line is resulting in a command not found.

I am running the script from the /var folder.

Here is the script:

#!/bin/bash

echo Hello World

I run it by typing the following:

bash testscript.sh

Why would this occur?

If you have Notepad++ and you get this .sh Error Message: "command not found" or this autoconf Error Message "line 615: ../../autoconf/bin/autom4te: No such file or directory".

On your Notepad++, Go to Edit -> EOL Conversion then check Macinthos(CR). This will edit your files. I also encourage to check all files with this command, because soon such an error will occur.

I was also having some of the Cannot execute command. Everything looked correct, but in fact I was having a non-breakable space   right before my command which was ofcourse impossible to spot with the naked eye:

if [[ "true" ]]; then
   highlight --syntax js "var i = 0;"
fi

Which, in Vim, looked like:

if [[ "true" ]]; then
  highlight --syntax js "var i = 0;"
fi

Only after running the Bash script checker shellcheck did I find the problem.

You can use bash -x scriptname.sh to trace it.

If the script does its job (relatively) well, then it's running okay. Your problem is probably a single line in the file referencing a program that's either not on the path, not installed, misspelled, or something similar.

One way is to place a set -x at the top of your script or run it with bash -x instead of just bash - this will output the lines before executing them and you usually just need to look at the command output immediately before the error to see what's causing the problem

If, as you say, it's the blank lines causing the problems, you might want to check what's actaully in them. Run:

od -xcb testscript.sh

and make sure there's no "invisible" funny characters like the CTRL-M (carriage return) you may get by using a Windows-type editor.

for executing that you must provide full path of that for example

/home/Manuel/mywrittenscript

Had the same problem. Unfortunately

dos2unix winfile.sh
bash: dos2unix: command not found

so I did this to convert.

 awk '{ sub("\r$", ""); print }' winfile.sh > unixfile.sh

and then

bash unixfile.sh

I also ran into a similar issue. The issue seems to be permissions. If you do an ls -l, you may be able to identify that your file may NOT have the execute bit turned on. This will NOT allow the script to execute. :)

As @artooro added in comment:

To fix that issue run chmod +x testscript.sh

use dos2unix on your script file.

You may want to update you .bashrc and .bash_profile files with aliases to recognize the command you are entering.

.bashrc and .bash_profile files are hidden files probably located on your C: drive where you save your program files.

Try chmod u+x testscript.sh

I know it from here: http://www.linuxquestions.org/questions/red-hat-31/running-shell-script-command-not-found-202062/

This might be trivial and not related to the OP's question, but I often made this mistaken at the beginning when I was learning scripting

VAR_NAME = $(hostname)
echo "the hostname is ${VAR_NAME}"  

This will produce 'command not found' response. The correct way is to eliminate the spaces

VAR_NAME=$(hostname)

I ran into this today, absentmindedly copying the dollar command prompt $ (ahead of a command string) into the script.

On Bash for Windows I've tried incorrectly to run

run_me.sh 

without ./ at the beginning and got the same error.

For people with Windows background the correct form looks redundant:

./run_me.sh

Problems with running scripts may also be connected to bad formatting of multi-line commands, for example if you have a whitespace character after line-breaking "\". E.g. this:

./run_me.sh \ 
--with-some parameter

(please note the extra space after "\") will cause problems, but when you remove that space, it will run perfectly fine.

Add the current directory ( . ) to PATH to be able to execute a script, just by typing in its name, that resides in the current directory:

PATH=.:$PATH