Bash script always prints “Command Not Found”

问题:

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. So the script works but there is always a Command Not Found statement printed on screen.

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

UPDATE - the problem appears to the blank lines. Each blank line is resulting in a command not found. Why would this occur?

回答1:

Make sure your first line is:

#!/bin/bash

Enter your path to bash if it is not /bin/bash

---

Try running:

dos2unix script.sh

That wil convert line endings, etc from Windows to unix format. i.e. it strips \\r (CR) from line endings to change them from \\r\\n (CR+LF) to \\n (LF).

More details about the dos2unix command (man page)

---

Another way to tell if your file is in dos/Win format:

cat scriptname.sh | sed \'s/\\r/<CR>/\'

The output will look something like this:

#!/bin/sh<CR>
<CR>
echo Hello World<CR>
<CR>

This will output the entire file text with <CR> displayed for each \\r character in the file.

回答2:

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

回答3:

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

回答4:

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.

回答5:

use dos2unix on your script file.

回答6:

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

/home/Manuel/mywrittenscript

回答7:

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.

回答8:

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/

回答9:

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

回答10:

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.

回答11:

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)

回答12:

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.

回答13:

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

回答14:

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

回答15:

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

回答16:

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.