I would like to run a few instances of my bash script foo.bash in background.
When I write for i in {1..10}; do ~/bin/foo.bash & ; done in the command line I get an error: bash: syntax error near unexpected token ;
Could you explain why this error occurs and how to fix the command?
& and ; are both command separators; you don't need (and can't have) both.
for i in {1..10}; do ~/bin/foo.bash & done
Related
I have the following bash code in a script file:
if [ 'false' == 'true' ]
then
write_map() >> 'groups.txt'
Groups='groups.txt'
fi
When I try to run the script, I get this message from bash, and nothing is run:
syntax error near unexpected token `>>'
Why is >> an "unexpected token?
Why is bash failing on code that is inside an "if" that won't be run?
This bash code was created by Cromwell wdl. write_map is a wdl function, not a bash function. Could that be what's breaking bash?
So, there were two issues
write_map was being called wrong in the wdl code that was the source for this bash code
When called correctly, write_map is turned into a file, and you can't >> a file (you have to cat it then >>)
In Bash in the terminal, it is impossible to run a command that ends with and & (being sent to the background) followed by another command (obviously with a ; between them). Why is that? Why can't you run anything with &; or $ ; in it?
I'm trying to recreate a 502 error and was trying to DoS a specific page in a testing server. I was trying to run this:
while true; do curl -s https://some.site.com/someImage.jpg > /dev/null &; echo blah ; done
as a "one-liner" in the terminal. However, I got this error:
-bash: syntax error near unexpected token `;'
However the commands work individually, and when I run the curl command not in the background it works as a loop as well. It also works when it write a one line script, "/tmp/curlBack.sh" that includes only
curl -s https://some.site.com/someImage.jpg > /dev/null &
And then run
while true; do bash /tmp/curlBack.sh ; echo blah ; done
Why am I getting this error and how do I fix it?
The problem is with the semi-colon after the ampersand (&):
An ampersand does the same thing as a semicolon or newline in that it indicates the end of a command, but it causes Bash to execute the command asynchronously.
BashSheet
Basically, it's as if you were to put double semi-colons back to back, that would cause a syntax error too.
To fix this problem, you simply need to remove the semi-colon, I tested it that way and it seems to be working:
while true; do curl -s https://some.site.com/someImage.jpg > /dev/null & echo blah ; done
The below code is being used to trigger a shell command using Jenkins file.
sh """
val=\$(echo ${val} | sed 's/[^a-zA-Z0-9]//g')
echo ${val}
"""
The below error reflects as part of the code :
/home/me/#tmp/abcd/script.sh: command substitution: line 4: syntax error near unexpected token `('
Any solution to the same ? Thanks in advance!
I want to ssh to a node and run a program in a background using &. So, the script looks like
#!/bin/bash
ssh NODENAME 'lmgrd -c license.lic &;
exit;'
However, the bash interpreter complains for syntax error near unexpected token ;. It seems that &
& already finisheds a command. So after & you simply don't use any terminator.
This script
#!/bin/sh
once=true
while $once do
stop & PID=$!
sleep 10M
if [$!=0]; then
start
break
else
kill $PID
fi
done
Gives
./restart.sh: line 18: syntax error near unexpected token `done'
./restart.sh: line 18: `done'
I don't understand, it had run previously on another unix system. Am i missing something?
EDIT
stop and start are functions that simply run stop.sh and start.sh respectively.
You seem to be missing a semicolon on line 4. Modifying it to read
while ${once}; do
should fix it.