In a Unix environment, I have a bash script that removes some files:
rm -f foo bar* baz*
My problem: not always the wildcard returns any result. And as a result of that, I fail to remove even 'foo' which always exists. The output written is "rm: No match".
A simple workaround would be to split the command:
rm -f foo
rm -f bar*
rm -f baz*
But it's a bad solution.
No it should work. Which shell is used ? Is rm an internal version or an external ? (Try /bin/rm instead to ensure the external version). You may have some shell option set that prevent you to execute the command in that case (this may depend on your shell).
Related
I'm currently struggling with running a .sh script I'm trying to trigger from Jenkins.
Within the Jenkins "execute shell" section, I'm connecting to a remote server (The Jenkins agent does not have right OS to build what I need.), using:
cp -r . /to/shared/drive/to/have/access/on/remote
ssh -t -t username#servername << EOF
cd /to/shared/drive/to/have/access/on/remote
source build.sh dev
exit
EOF
Inside build.sh, I'm exporting R_LIBS to build a package for different R versions.
...
for path in "${!rVersionPaths[#]}"; do
export R_LIBS="${path}"
Rscript -e 'install.packages(c("someDependency", "someOtherDependency"), repos="http://cran.r-project.org");'
...
Setting R_LIBS should functions here like setting lib within install.packages(...). For some reason the R_LIBS export doesn't get picked up. Also setting other env variables like http_proxy are ignored. This causes any requests outside the network to fail.
Is there any particular way of achieving this?
Maybe pass those variables with env, like
env R_LIBS="${path}" Rscript -e 'install.packages(c("someDependency", .....
Well i'm not able to comment on the question, so posting it as answer.
I had similar problem when calling remote shell script from Jenkins, the problem was somehow bash_profile variables were not loaded when called the script from Jenkins but locally it worked. Loading the bash profile in ssh connection solved it for me.
Add source to bash_profile in build.sh
. ~/.bash_profile OR source ~/.bash_profile
Or
Reload bash_profile in ssh connection
`ssh -t -t username#servername << EOF
. ~/.bash_profile
your commands here
exit
EOF
You can set that variable in the same command line like this:
R_LIBS="${path}" Rscript -e \
'install.packages(c("someDependency", "someOtherDependency"), repos="http://cran.r-project.org");'
It's possible to append more variables in this way. Note that this will set those environment variables only for the command being called after them (and its children processes as well).
You said that "R_LIBS export doesn't get picked up". Question Is the value UNSET? Or is it set to some other value & you are trying to override it?
It is possible that SSH may be invoking "/bin/sh -c". Based on the second answer to: Why does 'cd' command not work via SSH?, you can simplify the SSH command and explicitly invoke the build.sh script in Bash:
cp -r . /to/shared/drive/to/have/access/on/remote
ssh -t -t username#servername "cd /to/shared/drive/to/have/access/on/remote && bash -f build.sh dev"
This makes the SSH invocation more similar to invoking the command within a remote interactive shell. (You can avoid sourcing scripts and exporting variables.)
You don't need to export R_LIBSor env R_LIBS when it is possible to prefix any command with local environment variable overrides (agrees with Luis' answer):
...
for path in "${!rVersionPaths[#]}"; do
R_LIBS="${path}" Rscript -e 'install.packages(c("someDependency", "someOtherDependency"), repos="http://cran.r-project.org");'
...
The Rscript may be doing a lot with env vars. You can verify that you are setting the R_LIBS env var by replacing Rscript with the env command and observe the output:
...
for path in "${!rVersionPaths[#]}"; do
R_LIBS="${path}" env
...
According to this manual "Initialization at Start of an R Session", Rscript looks in several places to load "site and user files":
$R_PROFILE
$R_HOME/etc/Renviron
$R_HOME/etc/Renviron.site
$R_ENVIRON_USER
$R_PROFILE_USER
./.Rprofile
$HOME/.Rprofile
./.RData
The "Examples" section of that manual shows this:
## Not run:
## Example ~/.Renviron on Unix
R_LIBS=~/R/library
PAGER=/usr/local/bin/less
If you add the --vanilla command-line option to ignore all of these files, then you may get different results and know something in the site/init/environ files is affecting your R_LIBS! I cannot run this system myself. Hopefully we have given you some areas to investigate.
You probably don't want to source build.sh, just invoke it directly (i.e. remove the source command).
By source-ing the file your script is executed in the SSH shell (likely sh) rather than by bash, which it sounds like is what you intended.
Getting error in copying multiple files. Below command is copying only first file and giving error for rest of the files. Can someone please help me out.
Command:
scp $host:$(ssh -n $host "find /incoming -mmin -120 -name 2018*") /incoming/
Result:
user#host:~/scripts/OTA$ scp $host:$(ssh -n $host "find /incoming -mmin -120 -name 2018*") /incoming/
Password:
Password:
2018084session_event 100% |**********************************************************************************************************| 9765 KB 00:00
cp: cannot access /incoming/2018084session_event_log.195-10.45.40.9
cp: cannot access /incoming/2018084session_event_log.195-10.45.40.9_2_3
Your command uses Command Substitution to generate a list of files. Your assumption is that there is some magic in the "source" notation for scp that would cause multiple members of the list generated by your find command to be assumed to live on $host, when in fact your command might expand into something like:
scp remotehost:/incoming/someoldfile anotheroldfile /incoming
Only the first file is being copied from $host, because none of the rest include $host: at the beginning of the path. They're not found in your local /incoming directory, hence the error.
Oh, and in addition, you haven't escape the asterisk in the find command, so 2018* may expand to multiple files that are in the login directory for the user in question. I can't tell from here, it depends on your OS and shell configuration.
I should point out that you are providing yet another example of the classic Parsing LS problem. Special characters WILL break your command. The "better" solution usually offered for this problem tends to be to use a for loop, but that's not really what you're looking for. Instead, I'd recommend making a tar of the files you're looking for. Something like this might do:
ssh "$host" "find /incoming -mmin -120 -name 2018\* -exec tar -cf - {} \+" |
tar -xvf - -C /incoming
What does this do?
ssh runs a remote find command with your criteria.
find feeds the list of filenames (regardless of special characters) to a tar command as options.
The tar command sends its result to stdout (-f -).
That output is then piped into another tar running on your local machine, which extracts the stream.
If your tar doesn't support -C, you can either remove it and run a cd /incoming before the ssh, or you might be able to replace that pipe segment with a curly-braced command: { cd /incoming && tar -xvf -; }
The curly brace notation assumes a POSIX-like shell (bash, zsh, etc). The rest of this should probably work equally well in csh if that's what you're stuck with.
Limited warranty: Best Effort Only. Untested on animals or computers. Your milage may vary. May contain nuts.
If this doesn't work for you, poke at it until it does.
Why tail command -f option does not work well. when target file was null clear, then tail command does not write out anymote.
tail -f hoge&
cp /dev/null hoge
Tail also has a tail -F option which checks to see if the file has been changed.
From the man page:
The -F option implies the -f option, but tail will also check to see
if the file being followed has been renamed or rotated. The file is
closed and reopened when tail detects that the filename being read
from has a new inode number. The -F option is ignored if reading from
standard input rather than a file.
Is it possible to check if a directory exists and delete if it does,in Unix using a single command? I have situation where I use ANT 'sshexec' task where I can run only a single command in the remote machine. And I need to check if directory exists and delete it...
Why not just use rm -rf /some/dir? That will remove the directory if it's present, otherwise do nothing. Unlike rm -r /some/dir this flavor of the command won't crash if the folder doesn't exist.
Assuming $WORKING_DIR is set to the directory... this one-liner should do it:
if [ -d "$WORKING_DIR" ]; then rm -Rf $WORKING_DIR; fi
(otherwise just replace with your directory)
Try:
bash -c '[ -d my_mystery_dirname ] && run_this_command'
This will work if you can run bash on the remote machine....
In bash, [ -d something ] checks if there is directory called 'something', returning a success code if it exists and is a directory. Chaining commands with && runs the second command only if the first one succeeded. So [ -d somedir ] && command runs the command only if the directory exists.
Here is another one liner:
[[ -d /tmp/test ]] && rm -r /tmp/test
&& means execute the statement which follows only if the preceding
statement executed successfully (returned exit code zero)
I recommend opening documentation of rm command.
If open then you will see that there is a
-f flag does what you want. Example: rm -f -R ./my_folder
I have a script that looks like this
#!/bin/bash
function something() {
echo "hello world!!"
}
something | tee logfile
I have set the execute permission on this file and when I try running the file like this
$./script.sh
it runs perfectly fine, but when I run it on the command line like this
$sh script.sh
It throws up an error. Why does this happen and what are the ways in which I can fix this.
Running it as ./script.sh will make the kernel read the first line (the shebang), and then invoke bash to interpret the script. Running it as sh script.sh uses whatever shell your system defaults sh to (on Ubuntu this is Dash, which is sh-compatible, but doesn't support some of the extra features of Bash).
You can fix it by invoking it as bash script.sh, or if it's your machine you can change /bin/sh to be bash and not whatever it is currently (usually just by symlinking it - rm /bin/sh && ln -s /bin/bash /bin/sh). Or you can just use ./script.sh instead if that's already working ;)
If your shell is indeed dash and you want to modify the script to be compatible, https://wiki.ubuntu.com/DashAsBinSh has a helpful guide to the differences. In your sample it looks like you'd just have to remove the function keyword.
if your script is at your present working directory and you issue ./script.sh, the kernel will read the shebang (first line) and execute the shell interpreter that is defined. you can also call your script.sh by specifying the path of the interpreter eg
/bin/bash myscript.sh
/bin/sh myscript.sh
/bin/ksh myscript.sh etc
By the way, you can also put your shebang like this (if you don't want to specify full path)
#!/usr/bin/env sh
sh script.sh forces the script to be executed within the sh - shell.
while simply starting it from command line uses the shell-environemnt you're in.
Please post the error message for further answers.
Random though on what the error may be:
path specified in first line /bin/bash is wrong -- maybe bash is not installed?