I stumpled upon a strange behaviour that I can not explain. I tried to narrow down the problem. I have the following test testscript.sh script:
echo before
adb shell ls
echo after
If I run the script with bash -x testscript.sh, everything works as expected and I get the following output:
+ echo before
before
+ adb shell ls
acct
bin
bugreports
...
sdcard
storage
sys
system
ueventd.rc
vendor
+ echo before
before
But if I run the script as piped script with cat testscript.sh | bash -sx, I get the following output:
+ echo before
before
+ adb shell ls
acct
bin
bugreports
...
sdcard
storage
sys
system
ueventd.rc
vendor
The last echo after is not executed, and I can not figure out why. The script is running on an Ubuntu server 18.04. The adb is the one from the official Ubuntu package.
$ adb --version
Android Debug Bridge version 1.0.39
Version 1:8.1.0+r23-5~18.04
Installed as /usr/lib/android-sdk/platform-tools/adb
$ bash --version
GNU bash, version 4.4.20(1)-release (x86_64-pc-linux-gnu)
Please could someone enlight me, what is happening here.
When you run a script with bash scriptname, standard input of all the commands it runs is still connected to the terminal. So adb will read its standard input from the terminal.
When you redirect the input of bash, this redirection is inherited by adb. Unless you use the -n option to adb shell, it will read additional input from standard input and send it to the remote system as possible input for the command you run (it doesn't know that ls doesn't read standard input).
Change it to
adb shell -n ls
Related
I do this in a script:
read direc <<< $(basename `pwd`)
and I get:
Syntax error: redirection unexpected
in an ubuntu machine
/bin/bash --version
GNU bash, version 4.0.33(1)-release (x86_64-pc-linux-gnu)
while I do not get this error in another suse machine:
/bin/bash --version
GNU bash, version 3.2.39(1)-release (x86_64-suse-linux-gnu)
Copyright (C) 2007 Free Software Foundation, Inc.
Why the error?
Does your script reference /bin/bash or /bin/sh in its hash bang line? The default system shell in Ubuntu is dash, not bash, so if you have #!/bin/sh then your script will be using a different shell than you expect. Dash does not have the <<< redirection operator.
Make sure the shebang line is:
#!/bin/bash
or
#!/usr/bin/env bash
And run the script with:
$ ./script.sh
Do not run it with an explicit sh as that will ignore the shebang:
$ sh ./script.sh # Don't do this!
If you're using the following to run your script:
sudo sh ./script.sh
Then you'll want to use the following instead:
sudo bash ./script.sh
The reason for this is that Bash is not the default shell for Ubuntu. So, if you use "sh" then it will just use the default shell; which is actually Dash. This will happen regardless if you have #!/bin/bash at the top of your script. As a result, you will need to explicitly specify to use bash as shown above, and your script should run at expected.
Dash doesn't support redirects the same as Bash.
Docker:
I was getting this problem from my Dockerfile as I had:
RUN bash < <(curl -s -S -L https://raw.githubusercontent.com/moovweb/gvm/master/binscripts/gvm-installer)
However, according to this issue, it was solved:
The exec form makes it possible to avoid shell string munging, and
to RUN commands using a base image that does not contain /bin/sh.
Note
To use a different shell, other than /bin/sh, use the exec form
passing in the desired shell. For example,
RUN ["/bin/bash", "-c", "echo hello"]
Solution:
RUN ["/bin/bash", "-c", "bash < <(curl -s -S -L https://raw.githubusercontent.com/moovweb/gvm/master/binscripts/gvm-installer)"]
Notice the quotes around each parameter.
You can get the output of that command and put it in a variable. then use heredoc. for example:
nc -l -p 80 <<< "tested like a charm";
can be written like:
nc -l -p 80 <<EOF
tested like a charm
EOF
and like this (this is what you want):
text="tested like a charm"
nc -l -p 80 <<EOF
$text
EOF
Practical example in busybox under docker container:
kasra#ubuntu:~$ docker run --rm -it busybox
/ # nc -l -p 80 <<< "tested like a charm";
sh: syntax error: unexpected redirection
/ # nc -l -p 80 <<EOL
> tested like a charm
> EOL
^Cpunt! => socket listening, no errors. ^Cpunt! is result of CTRL+C signal.
/ # text="tested like a charm"
/ # nc -l -p 80 <<EOF
> $text
> EOF
^Cpunt!
do it the simpler way,
direc=$(basename `pwd`)
Or use the shell
$ direc=${PWD##*/}
Another reason to the error may be if you are running a cron job that updates a subversion working copy and then has attempted to run a versioned script that was in a conflicted state after the update...
On my machine, if I run a script directly, the default is bash.
If I run it with sudo, the default is sh.
That’s why I was hitting this problem when I used sudo.
In my case error is because i have put ">>" twice
mongodump --db=$DB_NAME --collection=$col --out=$BACKUP_LOCATION/$DB_NAME-$BACKUP_DATE >> >> $LOG_PATH
i just correct it as
mongodump --db=$DB_NAME --collection=$col --out=$BACKUP_LOCATION/$DB_NAME-$BACKUP_DATE >> $LOG_PATH
Before running the script, you should check first line of the shell script for the interpreter.
Eg:
if scripts starts with /bin/bash , run the script using the below command
"bash script_name.sh"
if script starts with /bin/sh, run the script using the below command
"sh script_name.sh"
./sample.sh - This will detect the interpreter from the first line of the script and run.
Different Linux distributions having different shells as default.
I have a bash script lets say test.sh. This script contains the following:
#!/bin/bash
echo "khaled"
ads2 svcd&
This script simply prints my name (just for test purposes) and execute ads-service application in the background. When i run the script on my ubuntu, it works correctly. As a test i checked which programs run on the kernel
As you see. ads2 runs and has 12319 process-id.
Now what I'm trying to do is to run the script on the ubuntu, however remotely from a windows pc.
Therefore i opened command-line on windows and executed the following command:
ssh nvidia#ubuntu ip-address ~/test.sh
And i get the following
As you see the scripts run and prints khaled,however on windows command line and what i want is that the script is executed on the ubuntu. this justify why the lineads2 svcd& doe not do anything, neither on windows (which makes sense, since ads2 is installed on ubuntu) nor on linux.
So how can i execute the script on ubuntu ?
thanks in advance
Use the full path to start ads2. When using remote SSH your environment variables may be different than in a local shell.
#!/bin/bash
echo "khaled"
/home/nvidia/ads2 svcd&
Not sure where ads2 is located.
Try the following to locate it on your Ubuntu local shell.
command -v ads2
You may also need nohup to persist the process beyond the life of the SSH session.
If you have the script on the remote server and you want to run this, you would add back ticks,
ssh user#server './test/file.sh'
The script's output would be sent to your local machine, as if you ran the command from your local machine.
I'm in trouble with response Values of a phyton script (face_detection).
If I run it directly in the console, everything works pretty well.
If I run it as Part of a shell script, no response apear.
I already checked:
1.) image and scripts are usable by user www-data (at the end it should run as system-request from php). I checked it by sudo -u www-data ..
2.) Also also checked a much simpler command ("ls -l $1"), which brings the expected reponse. So only the python script doesnt work (as sub from bash script).
Now, I have NO Idea what else may be wrong in my code. Any Help would be very apreciated!
Regards Rene´
Some Background info:
Ubuntu 14.4, Kernel 3.13.0-24-generic
PHP 5.5.9-1ubuntu4.26
GNU bash, version 4.3.8(1)-release
face_recognise (https://github.com/ageitgey/face_recognition) V 1.2.3
on terminal:
/usr/local/bin/face_detection /var/www/1545249278.jpg
response is:
/var/www/1545249278.jpg,166,879,701,344 (= correct)
via bash-script:
#!/bin/bash
facePosition=`/bin/bash -c \"/usr/bin/python3 /usr/local/bin/face_detection $1\"`
printf $facePosition
response is: (None/empty = wrong)
I also checked this variations:
facePosition=`/bin/bash -c \"/usr/local/bin/face_detection $1 | /usr/bin/cut -d ',' -f2\"`
facePosition=`/bin/bash -c \"/usr/bin/python3 /usr/local/bin/face_detection $1\"`
facePosition=`env python3 /usr/local/bin/face_detection $1`
I have created a startup Linux script for a board that runs Debian jessie Armbian 8.1. I need at startup to run at command in a modem attached to it via USB interface. I've put the script inside rc.local:
#!/bin/sh -e
cd /home/user/Script/
sh script.sh
exit 0
In the folder Script I have a script:
#!/bin/sh
minicom -S at_command.txt
The at_command contains:
send at+creg=1
send exit
! killall minicom
The issue is that when I run the script manually it works correctly,
however when I start the the board the at commands do not execute.
Since the board is Debian I also followed the link: ttp://www.stuffaboutcode.com/2012/06/raspberry-pi-run-program-at-start-up.html and to adapt the script to run according LSBInitScripts but I got the same behavior. When running sudo /etc/init.d/myScript start manually everything works great, but after Linux startup no at_command is executed. I added in the rc.local the following commands for debugging:
set -x;
exec 2>>/home/user/Script/minicom-rc.log;
date +"$0 %c" >&2
And in the generated log file I got this printout:
+ date +/etc/rc.local %c
/etc/rc.local Fri 02 Mar 2018 04:02:43 PM EET
+ cd /home/user/Script/
+ sh script.sh
No cursor motion capability (cm)
What I have done wrong?
I am guessing it is related to there being no terminal during startup.
Maybe try adding the following line before starting minicom:
export TERM=linux-c-nc
In this scenario you alternatively use my atinout program which is a program specifically made for sending AT commands to a modem from the command line (assuming the modem is /dev/ttyUSB0):
echo at+creg=1 | atinout - /dev/ttyUSB0 -
or possibly
atinout /home/user/at_commands.txt /dev/ttyUSB0 /dev/null
How do you run a shell script in a new terminal in Linux from a terminal like "start test.bat" in Windows, also it should be working in the console mode.
Here's a simple example to get you started:
To write a shell script, do this on your command prompt:
echo -e '#!/bin/sh\n echo "hello world"' > abc.sh
This writes:
#!/bin/sh
echo "hello world"
To a file called abc.sh
Next, you want to set it to executable by:
chmod +x abc.sh
Now, you can run it by:
./abc.sh
And you should see:
hello world
On your terminal.
To run it in a new terminal, you can do:
gnome-terminal -x ./abc.sh
or, if it's xterm:
xterm -e ./abc.sh
Here's a list of different terminal emulators.
Alternatively, you just run it in your current terminal, but background it instead by:
./abc.sh &
I came here wanting to figure out how to make a script spawn a terminal and run it self in it, so for those who want to do that I figured out this solution:
if [ ! -t 0 ]; then # script is executed outside the terminal?
# execute the script inside a terminal window with same arguments
x-terminal-emulator -e "$0" "$#"
# and abort running the rest of it
exit 0
fi
For gnome try this.
Replace ls with the command you want to run
gnome-terminal -x sh -c "ls|less"
I hope this is what you want
As of January 2020, the -e and -x option in gnome-terminal still run properly but throw out the following warnings:
For -e:
# Option “-e” is deprecated and might be removed in a later version
of gnome-terminal.
# Use “-- ” to terminate the options and put the command line to
execute after it.
For -x:
# Option “-x” is deprecated and might be removed in a later version
of gnome-terminal.
# Use “-- ” to terminate the options and put the command line to
execute after it.
Based on that information above, I confirmed that you can run the following two commands without receiving any warning messages:
gnome-terminal -- /bin/sh -c '<your command>'
gnome-terminal -- ./<your script>.sh
I hope this helps anyone else presently having this issue :)