As the question specifics ,i am getting this error while executing my bash script
In exact terms i get following error
bash: line 26: /dev/tty: No such device or address
bash: line 29: /dev/tty: No such device or address
Here are the concerned Line 26 and 29 in script respectively which causes the issue
read -e -p "Paste the links : " links </dev/tty
read -e -p "Enter your input : " sub </dev/tty
If someone wonders, i cannot simply remove writing to </dev/tty from line 26 and 29 , it causes different issues .. So basically i need fix or get alternative for writing to /dev/tty
I am executing my script by running -
curl raw_link | bash
Preferably i want a solution which only requires me to my edit my existing script .i don't want to run the script after saving it locally or execute it using any other way apart from curl raw_link | bash
ls -l /dev/tty returns the following
crw-rw-rw- 1 root root 5, 0 Aug 8 09:28 /dev/tty
ls -l </dev/tty returns the following
/bin/bash: /dev/tty: No such device or address
Also i would like to mention that this issue doesn't seem to be happening on every machine , i intend to use this script on Google Colab where i definitely do get this issue
To fix the bash error, you can try this workaround :
tty=$(readlink /proc/$$/fd/2)
read ... < $tty
$tty contains the actual tty device name.
Related
This is my first time working with SNMP, but after reading the SNMP pages I'm still having trouble getting a simple shell script to run when receiving a trap.
My /etc/snmp/snmptrapd.conf file looks like this:
# Example configuration file for snmptrapd
#
# No traps are handled by default, you must edit this file!
#
disableAuthorization yes
authCommunity log,execute,net public
# the generic traps
traphandle default /usr/local/bin/snmptrapd.sh
The snmptrapd.sh script just says "hello".
#!/bin/sh
echo "hello"
The script is executable and runs when executed independently:
> /usr/local/bin/snmptrapd.sh
hello
The snmptrapd is running as a background process:
> ps -ef | grep snmp
root 29477 1 0 14:49 ? 00:00:00 /usr/sbin/snmptrapd -Lsd -p /var/run/snmptrapd.pid -Cc /etc/snmp/snmptrapd.conf
And yet when I send a trap locally using snmptrap nothing happens:
> snmptrap -v 2c -c public localhost "" NET-SNMP-EXAMPLES-MIB::netSnmpExampleHeartbeatNotification netSnmpExampleHeartbeatRate i 123456
>
Now it seems that the trap does get logged, because the system log file (/var/log/messages) has the following entry:
Aug 8 15:46:10 <server_name> snmptrapd[29477]: 2017-08-08 15:46:10 localhost
[UDP: [127.0.0.1]:44928->[127.0.0.1]]:#012DISMAN-EVENT-MIB::sysUpTimeInstance =
Timeticks: (1338382434) 154 days, 21:43:44.34#011SNMPv2-MIB::snmpTrapOID.0 =
OID: NET-SNMP-EXAMPLES-MIB::netSnmpExampleHeartbeatNotification#011NET-SNMP-EXAMPLES-MIB::netSnmpExampleHeartbeatRate
= INTEGER: 123456
As far as I can see everything is set up correctly. If so, why is the trap handle not working and how can one check why the trap doesn't trigger the script?
Thanks in advance.
EDIT: When I added the -Ci option to the snmptrapd command line options I got the following error:
No log handling enabled - turning on stderr logging
: Unknown Object Identifier (Sub-id not found: (top) -> )
OK, so after looking around some more I found the answer.
The reason that we are not seeing the output is because snmptrapd is being run as a daemon and doesn't send its standard output to the console. One can replace this with
echo "hello" > $HOME/output.txt
and the word 'hello' appears in the output.txt file.
See also http://www.linuxquestions.org/questions/linux-newbie-8/net-snmp-trap-handling-4175420577/
and
https://superuser.com/questions/823435/where-to-log-stdout-and-stderr-of-a-daemon
This question already has answers here:
Are shell scripts sensitive to encoding and line endings?
(14 answers)
Closed 4 years ago.
I have a shell script with a command that seems like it should work, but instead it fails with an odd wrapped/truncated/corrupted error message. Example:
$ ls -l myfile
-rw-r----- 1 me me 0 Aug 7 12:36 myfile
$ cat myscript
ls -l myfile
$ bash myscript
: No such file or directory
The file clearly exist, but even if I didn't, this is the kind of error message I would normally get:
$ ls -l idontexist
ls: cannot access idontexist: No such file or directory
Notice how it includes the tool name ls, a message string and the filename while mine does not.
Here's what I get if I try to use mysql instead. The error message looks like it's been wrapped, and now starts with a quote:
Command: mysql -h myhost.example.com
Expected: ERROR 2005 (HY000): Unknown MySQL server host 'myhost.example.com' (0)
Actual: ' (0) 2005 (HY000): Unknown MySQL server host 'myhost.example.com
And here's my trivial ssh command that should work, or at least give a normal error message, but which instead is wrapped to start with a colon and ends with strange clobbering:
Command: ssh myhost
Expected: ssh: Could not resolve hostname myhost: Name or service not known
Actual: : Name or service not knownname myhost
Why does this happen, and how do I fix it?
TL;DR: Your script or data has Windows style CRLF line endings.
Convert to Unix style by deleting the carriage returns.
How do I check if my script or data has carriage returns?
They're detectable as ^M in the output of cat -v yourscript:
$ cat -v myscript
ls -l myfile^M
If your script doesn't have them, your data might -- especially if reading from ini/csv files or curl:
hostname=$(curl https://example.com/loginhost.txt)
ssh "$hostname" # Shows strange error
echo "$hostname" | cat -v # Shows myhost^M
How do I remove them?
Set your editor to save the file with Unix line endings, aka "line terminators" or "end-of-line characters", and resave it.
You can also remove them from a command line with dos2unix yourscript or cat yourscript | tr -d '\r' > fixedscript.
If found in your data, you can pipe your source through tr -d '\r':
hostname=$(curl https://example.com/loginhost.txt | tr -d '\r')
Why do carriage returns cause strange error messages?
The "carriage return" character, aka CR or \r, causes the cursor to move to the start of the line, and continue printing from there. In other words, it starts overwriting the line from the start. This is why they wrap strangely:
Intended: ssh: Could not resolve hostname myhost\r: Name or service not known
Written: ssh: Could not resolve hostname myhost\r
Overwritten: : Name or service not known
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Result: : Name or service not knownname myhost
This question already has answers here:
Are shell scripts sensitive to encoding and line endings?
(14 answers)
Closed 4 years ago.
I have a shell script with a command that seems like it should work, but instead it fails with an odd wrapped/truncated/corrupted error message. Example:
$ ls -l myfile
-rw-r----- 1 me me 0 Aug 7 12:36 myfile
$ cat myscript
ls -l myfile
$ bash myscript
: No such file or directory
The file clearly exist, but even if I didn't, this is the kind of error message I would normally get:
$ ls -l idontexist
ls: cannot access idontexist: No such file or directory
Notice how it includes the tool name ls, a message string and the filename while mine does not.
Here's what I get if I try to use mysql instead. The error message looks like it's been wrapped, and now starts with a quote:
Command: mysql -h myhost.example.com
Expected: ERROR 2005 (HY000): Unknown MySQL server host 'myhost.example.com' (0)
Actual: ' (0) 2005 (HY000): Unknown MySQL server host 'myhost.example.com
And here's my trivial ssh command that should work, or at least give a normal error message, but which instead is wrapped to start with a colon and ends with strange clobbering:
Command: ssh myhost
Expected: ssh: Could not resolve hostname myhost: Name or service not known
Actual: : Name or service not knownname myhost
Why does this happen, and how do I fix it?
TL;DR: Your script or data has Windows style CRLF line endings.
Convert to Unix style by deleting the carriage returns.
How do I check if my script or data has carriage returns?
They're detectable as ^M in the output of cat -v yourscript:
$ cat -v myscript
ls -l myfile^M
If your script doesn't have them, your data might -- especially if reading from ini/csv files or curl:
hostname=$(curl https://example.com/loginhost.txt)
ssh "$hostname" # Shows strange error
echo "$hostname" | cat -v # Shows myhost^M
How do I remove them?
Set your editor to save the file with Unix line endings, aka "line terminators" or "end-of-line characters", and resave it.
You can also remove them from a command line with dos2unix yourscript or cat yourscript | tr -d '\r' > fixedscript.
If found in your data, you can pipe your source through tr -d '\r':
hostname=$(curl https://example.com/loginhost.txt | tr -d '\r')
Why do carriage returns cause strange error messages?
The "carriage return" character, aka CR or \r, causes the cursor to move to the start of the line, and continue printing from there. In other words, it starts overwriting the line from the start. This is why they wrap strangely:
Intended: ssh: Could not resolve hostname myhost\r: Name or service not known
Written: ssh: Could not resolve hostname myhost\r
Overwritten: : Name or service not known
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Result: : Name or service not knownname myhost
Per the title, I'm getting the following warning when I try to scp through an ssh tunnel. In my case, I cannot scp directly to foo because port 1234 on device foo is being forwarded to another machine bar on a private network (and bar is the machine that is giving me a tunnel to 192.168.1.23).
$ # -f and -N don't matter and are only to run this example in one terminal
$ ssh -f -N -p 1234 userA#foo -L3333:192.168.1.23:22
$ scp -P 3333 foo.py ubuntu#localhost:
ubuntu#localhost's password:
stty: standard input: Inappropriate ioctl for device
foo.py 100% 1829 1.8KB/s 00:00
Does anyone know why I might be getting this warning about Inappropriate ioctl for device?
I got the exact same problem when I included the following line on my ~/.bashrc:
stty -ixon
The purpose of this line was to allow the use of Ctrl-s in reverse search of bash.
This gmane link has a solution: (original link dead) => Web Archive version of gmane link
'stty' applies to ttys, which you have for interactive login sessions.
.kshrc is executed for all sessions, including ones where stdin isn't
a tty. The solution, other than moving it to your .profile, is to
make execution conditional on it being an interactive shell.
There are several ways to check for interecative shell. The following solves the problem for bash:
[[ $- == *i* ]] && stty -ixon
Got the same issue while executing the script remotely. After many tries didn't get any luck to solve this error. Then got an article to run a shell script through ssh. This was an issue related to ssh, not any other command. ssh -t "command" -t will allocate a pseudo TTY to the ssh and this error won't come.
at the end i created a blank .cshrc file ( for ubuntu 18.04). worked
I'm trying to use bashdb on CentOS 4.1 (unfortunately I can't choose a different/newer OS).
I installed bash 4.2 then bashdb 4.2-0.8. THere were no complaints from configure, make, make checks, or make install: everything looked peachy.
But trying to use bashdb either as 'bash --debugger myscript' or 'bashdb myscript' always gets this error:
[bot#sjbld1 bin]$ bashdb -- putxen.sh
bash debugger, bashdb, release 4.2-0.8
Copyright 2002, 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Rocky Bernstein
This is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
/usr/local/share/bashdb/lib/setshow.sh: line 91: /dev/pts/2: Permission denied
/usr/local/share/bashdb/lib/setshow.sh: line 91: /dev/pts/2: Permission denied
/usr/local/share/bashdb/lib/setshow.sh: line 91: /dev/pts/2: Permission denied
/usr/local/share/bashdb/lib/setshow.sh: line 91: /dev/pts/2: Permission denied
[bot#sjbld1 bin]$
There's no line 91 in setshow.sh, and there's no /dev/pts in a directory listing of /dev.
Any suggestions how to proceed will be very much appreciated. I'm taking on a broken mess of shell script, and I'm not hot at bash (or Linux) and hope for more intimate debugging than set -x and echo statements.
Thanks
For completeness I should have added the bash script I was trying to use as bashdb test, as requested by konsolebox, though the "Permission denied" problem occurs with any code, and is solved by using sudo as suggested by Red Cricket. Here's the script:
[bot#sjcpbrvpxbld1 bin]$ cat putxen.sh
if [ x$1 == x ]
then
echo must have filename as parameter
exit 1
fi
if [ -e $1 ]
then
echo $1 found
else
echo cannot find ./$1
exit 1
fi
FTPTGT=10.10.10.25
DIRTGT=xva
echo ftp upload file to $DIRTGT directory on $FTPTGT
ftp -n $FTPTGT <<EOF
user anonymous pass
hash
bin
cd $DIRTGT
put "$1"
bye
Since programs often have stdout and stderr redirected, bashdb tries to write its output to a tty, unless directed otherwise; bashdb determines the console running the tty command.
Normally you don't need to run bashdb as root. But for reasons that are a mystery here, the user you are running bashdb as, is not able to write to the tty registered to it. That is:
echo hi > $(tty)
will probably give you the same "Permission denied". Probably ls -l $(tty) will tell you what's up there.
However, as suggested in the comments, you can workaround this by running as root such as via sudo: e.g.
sudo bashdb -- putxen.sh
Another workaround is to add your user to the group, e.g. tty that is listed when you run ls -l $(tty).