Say I have a file at the URL http://mywebsite.example/myscript.txt that contains a script:
#!/bin/bash
echo "Hello, world!"
read -p "What is your name? " name
echo "Hello, ${name}!"
And I'd like to run this script without first saving it to a file. How do I do this?
Now, I've seen the syntax:
bash < <(curl -s http://mywebsite.example/myscript.txt)
But this doesn't seem to work like it would if I saved to a file and then executed. For example readline doesn't work, and the output is just:
$ bash < <(curl -s http://mywebsite.example/myscript.txt)
Hello, world!
Similarly, I've tried:
curl -s http://mywebsite.example/myscript.txt | bash -s --
With the same results.
Originally I had a solution like:
timestamp=`date +%Y%m%d%H%M%S`
curl -s http://mywebsite.example/myscript.txt -o /tmp/.myscript.${timestamp}.tmp
bash /tmp/.myscript.${timestamp}.tmp
rm -f /tmp/.myscript.${timestamp}.tmp
But this seems sloppy, and I'd like a more elegant solution.
I'm aware of the security issues regarding running a shell script from a URL, but let's ignore all of that for right now.
source <(curl -s http://mywebsite.example/myscript.txt)
ought to do it. Alternately, leave off the initial redirection on yours, which is redirecting standard input; bash takes a filename to execute just fine without redirection, and <(command) syntax provides a path.
bash <(curl -s http://mywebsite.example/myscript.txt)
It may be clearer if you look at the output of echo <(cat /dev/null)
This is the way to execute remote script with passing to it some arguments (arg1 arg2):
curl -s http://server/path/script.sh | bash /dev/stdin arg1 arg2
For bash, Bourne shell and fish:
curl -s http://server/path/script.sh | bash -s arg1 arg2
Flag "-s" makes shell read from stdin.
Use:
curl -s -L URL_TO_SCRIPT_HERE | bash
For example:
curl -s -L http://bitly/10hA8iC | bash
Using wget, which is usually part of default system installation:
bash <(wget -qO- http://mywebsite.example/myscript.txt)
You can also do this:
wget -O - https://raw.github.com/luismartingil/commands/master/101_remote2local_wireshark.sh | bash
The best way to do it is
curl http://domain/path/to/script.sh | bash -s arg1 arg2
which is a slight change of answer by #user77115
You can use curl and send it to bash like this:
bash <(curl -s http://mywebsite.example/myscript.txt)
I often using the following is enough
curl -s http://mywebsite.example/myscript.txt | sh
But in a old system( kernel2.4 ), it encounter problems, and do the following can solve it, I tried many others, only the following works
curl -s http://mywebsite.example/myscript.txt -o a.sh && sh a.sh && rm -f a.sh
Examples
$ curl -s someurl | sh
Starting to insert crontab
sh: _name}.sh: command not found
sh: line 208: syntax error near unexpected token `then'
sh: line 208: ` -eq 0 ]]; then'
$
The problem may cause by network slow, or bash version too old that can't handle network slow gracefully
However, the following solves the problem
$ curl -s someurl -o a.sh && sh a.sh && rm -f a.sh
Starting to insert crontab
Insert crontab entry is ok.
Insert crontab is done.
okay
$
Also:
curl -sL https://.... | sudo bash -
Just combining amra and user77115's answers:
wget -qO- https://raw.githubusercontent.com/lingtalfi/TheScientist/master/_bb_autoload/bbstart.sh | bash -s -- -v -v
It executes the bbstart.sh distant script passing it the -v -v options.
Is some unattended scripts I use the following command:
sh -c "$(curl -fsSL <URL>)"
I recommend to avoid executing scripts directly from URLs. You should be sure the URL is safe and check the content of the script before executing, you can use a SHA256 checksum to validate the file before executing.
instead of executing the script directly, first download it and then execute
SOURCE='https://gist.githubusercontent.com/cci-emciftci/123123/raw/123123/sample.sh'
curl $SOURCE -o ./my_sample.sh
chmod +x my_sample.sh
./my_sample.sh
This way is good and conventional:
17:04:59#itqx|~
qx>source <(curl -Ls http://192.168.80.154/cent74/just4Test) Lord Jesus Loves YOU
Remote script test...
Param size: 4
---------
17:19:31#node7|/var/www/html/cent74
arch>cat just4Test
echo Remote script test...
echo Param size: $#
If you want the script run using the current shell, regardless of what it is, use:
${SHELL:-sh} -c "$(wget -qO - http://mywebsite.example/myscript.txt)"
if you have wget, or:
${SHELL:-sh} -c "$(curl -Ls http://mywebsite.example/myscript.txt)"
if you have curl.
This command will still work if the script is interactive, i.e., it asks the user for input.
Note: OpenWRT has a wget clone but not curl, by default.
bash | curl http://your.url.here/script.txt
actual example:
juan#juan-MS-7808:~$ bash | curl https://raw.githubusercontent.com/JPHACKER2k18/markwe/master/testapp.sh
Oh, wow im alive
juan#juan-MS-7808:~$
This question already has answers here:
Bash: Syntax error: redirection unexpected
(9 answers)
Closed 8 years ago.
I have the following script:
#!/bin/sh
# Use the PhiPack software on our two aligned sets of sequences...
mkdir FcFeABC
cd FcFeABC
../bin/PhiPack/Phi -f ../../Data/Real_Sequences_and_Networks/FcFeABC_alignment.fas -o -v -w 10 -g
cd -
mkdir FcL10
cd FcL10
../bin/PhiPack/Phi -f ../../Data/Real_Sequences_and_Networks/FcL10_alignment.fas -o -v -w 10 -g
cd -
# Use the PhiPack software on the simulated Datasets...
cd ../Data/Simulated_Sequences_and_Networks/Constant_Sex/Theta\ =\ 0.066/Theta\ =\ 0.066/Medium/CutSequences/;
rmus=($(ls -d *.fas))
cd -
absfiles=(../Data/Simulated_Sequences_and_Networks/Constant_Sex/Theta\ =\ 0.066/Theta\ =\ 0.066/Medium/CutSequences/*.fas)
if [ ${#rmus[#]} = ${#absfiles[#]} ]
then
mkdir ${rmus[#]}
for ((i=0; i<${#absfiles[#]}; i++));
do
cd ${rmus[$i]}
.../bin/PhiPack/Phi -f ${absfiles[$i]} -o -v -w 10 -g
cd -
done
else
echo "Error, Number of files created and files to be read differs"
fi
Which hit's an error at line 16:
./runPhiTests.sh: 16: ./runPhiTests.sh: Syntax error: "(" unexpected
Which is this line:
rmus=($(ls -d *.fas))
I don't understand why the '(' is unexpected - it's a simple assignment of the results of ls to an array.
Thanks,
Ben W.
You aren't running it with bash. You are running with /bin/sh from your shebang line #!/bin/sh.
Either run with bash explicitly bash runPhiTests.sh or fix your shebang line #!/bin/bash.
Try to use #!/bin/bash instead of sh.
I'm trying to write a simple bash script that executes a command with one string variable. Upon execution bash adds single quotes to the string variable making the command useless. How do I execute the command without the quotes from the bash script?
#!/bin/bash
key=$(echo $1 | tr '[:lower:]' '[:upper:]')
sudo tee /proc/acpi/bbswitch \<\<\<$key
the output I get is
~/scripts$ bash -x nvidia on
++ echo on
++ tr '[:lower:]' '[:upper:]'
+ key=ON
+ sudo tee /proc/acpi/bbswitch '<<<ON'
the two commands I want to run without the quotes are either
sudo tee /proc/acpi/bbswitch <<<ON
or
sudo tee /proc/acpi/bbswitch <<<OFF
The problem isn't the quotes, it's that sudo doesn't execute the command via the shell. So metacharacters like <<< don't have any special meaning when they're given as sudo arguments. You need to invoke the shell explicitly:
sudo bash -c "tee /proc/acpi/bbswitch <<<$key"
But there doesn't really seem to be a need to use a here-string for this. Just use:
echo "$key" | sudo tee /proc/acpi/bbswitch
There's no need to quote the <<< operator. sudo doesn't read from its standard input by default; it passes it through to the command it runs.
sudo tee /proc/acpi/bbswitch <<< $key
I am trying to disable RHN check when running yum on 1000 servers. It is done by:
Editing this file /etc/yum/pluginconf.d/rhnplugin.conf
[main]
enabled = 0
I wrote a script to do this remotely. We are using individual accounts and I need to execute this command using SUDO:
for HOST in $(cat serverlist ) ; do echo $HOST; ssh -o ConnectTimeout=5 -oStrictHostKeyChecking=no $HOST -t 'sudo cp /etc/yum/pluginconf.d/rhnplugin.conf /etc/yum/pluginconf.d/rhnplugin.$(date +%F) ; sudo sed -i -e "s/1/0/g" /etc/yum/pluginconf.d/rhnplugin.conf ' ; done
I know it is a long line but why does it not work?
All individual commands work on their own
sudo cp /etc/yum/pluginconf.d/rhnplugin.conf /etc/yum/pluginconf.d/rhnplugin.$(date +%F)
sudo sed -i -e "s/1/0/g" /etc/yum/pluginconf.d/rhnplugin.conf
have tried escaping the special chars:
sudo sed -i -e "s\/1\/0\/g" /etc/yum/pluginconf.d/rhnplugin.conf
But I get an error all the time:
sed: -e expression #1, char 1: unknown command: `?'
Thanks for your help.
The sudo(1) command expects a pseudo-teletype (pty) and fails if it does not see one. Rewrite your command line to use su(1) instead. Use your local sudo(1) configuration to limit access to this script so only the select few can execute the script.
I actually found the answer to this question, or rather workaround. See the snippet below, where I got to -as root- ssh as me (szymonri) to other host, then invoke sed command as root in order to edit /etc/hosts file. All thanks to base64 magic.
ME=`echo -e "$(hostname -I | awk '{print $1}')\toverlord"`
B64ENC=`echo "sed -i 's/.*overlord/$ME/g' /etc/hosts" | base64`
su - szymonri sh -c "ssh jetson bash -c \\\"echo $B64ENC \| base64 --decode \| sudo bash \\\""
line: I"m obtaining m yown IP address as an /etc/hosts line
line: I'm base64 encoding sed command with the first line in it.
line: I'm invoking the SSH shenannigan, where I su as regular user, ssh to another box as the user, and use power of sudo to edit the file.
I am trying to run a series of commands in parallel through xargs. I created a null-separated list of commands in a file cmd_list.txt and then attempted to run them in parallel with 6 threads as follows:
cat cmd_list.txt | xargs -0 -P 6 -I % bash -c %
However, I get the following error:
bash: line 0: fg: no job control
I've narrowed down the problem to be related to the length of the individual commands in the command list. Here's an example artificially-long command to download an image:
mkdir a-very-long-folder-de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8
wget --no-check-certificate --no-verbose -O a-very-long-folder-de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8/blah.jpg http://d4u3lqifjlxra.cloudfront.net/uploads/example/file/48/accordion.jpg
Just running the wget command on its own, without the file list and without xargs, works fine. However, running this command at the bash command prompt (again, without the file list) fails with the no job control error:
echo "wget --no-check-certificate --no-verbose -O a-very-long-folder-de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8/blah.jpg http://d4u3lqifjlxra.cloudfront.net/uploads/example/file/48/accordion.jpg" | xargs -I % bash -c %
If I leave out the long folder name and therefore shorten the command, it works fine:
echo "wget --no-check-certificate --no-verbose -O /tmp/blah.jpg http://d4u3lqifjlxra.cloudfront.net/uploads/example/file/48/accordion.jpg" | xargs -I % bash -c %
xargs has a -s (size) parameter that can change the max size of the command line length, but I tried increasing it to preposterous sizes (e.g., 16000) without any effect. I thought that the problem may have been related to the length of the string passed in to bash -c, but the following command also works without trouble:
bash -c "wget --no-check-certificate --no-verbose -O a-very-long-folder-de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8/blah.jpg http://d4u3lqifjlxra.cloudfront.net/uploads/example/file/48/accordion.jpg"
I understand that there are other options to run commands in parallel, such as the parallel command (https://stackoverflow.com/a/6497852/1410871), but I'm still very interested in fixing my setup or at least figuring out where it's going wrong.
I'm on Mac OS X 10.10.1 (Yosemite).
It looks like the solution is to avoid the -I parameter for xargs which, per the OS X xargs man page, has a 255-byte limit on the replacement string. Instead, the -J parameter is available, which does not have a 255-byte limit.
So my command would look like:
echo "wget --no-check-certificate --no-verbose -O a-very-long-folder-de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8/blah.jpg http://d4u3lqifjlxra.cloudfront.net/uploads/example/file/48/accordion.jpg" | xargs -J % bash -c %
However, in the above command, only the portion of the replacement string before the first whitespace is passed to bash, so bash tries to execute:
wget
which obviously results in an error. My solution is to ensure that xargs interprets the commands as null-delimited instead of whitespace-delimited using the -0 parameter, like so:
echo "wget --no-check-certificate --no-verbose -O a-very-long-folder-de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8de090952623b4865c2c34bd6330f8a423ed05ed8/blah.jpg http://d4u3lqifjlxra.cloudfront.net/uploads/example/file/48/accordion.jpg" | xargs -0 -J % bash -c %
and finally, this works!
Thank you to #CharlesDuffy who provided most of this insight. And no thank you to my OS X version of xargs for its poor handling of replacement strings that exceed the 255-byte limit.
I suspect it's the percent symbol, and your top shell complaining.
cat cmd_list.txt | xargs -0 -P 6 -I % bash -c %
Percent is a metacharacter for job control. "fg %2", e.g. "kill %4".
Try escaping the percents with a backslash to signal to the top shell that it should not try to interpret the percent, and xargs should be handed a literal percent character.
cat cmd_list.txt | xargs -0 -P 6 -I \% bash -c \%