Currently I am learning bash scripting.
So, I wanted to know how can I modify the output of linux command.
To be specific, I entered a command and after pressing enter, every line should start with an '->' or any symbol.
E.g: In arch-linux, when we use pacman or yaourt to install packages,
we get "==>" "->" "::" proceeding with some information.
I want output somewhat similar to that.
Not sure I get what you are trying to do but… are you looking for something such as:
function pprint() {
echo "==> " $1
}
Which you can use as such in your scripts:
pprint "Hey there"
To output the following:
===> Hey there
Related
I am running Windows 10 and am trying to save the error output of a test.sh file to a text file.
So I created the test.sh file and wrote an unkown command in it (i.e. "blablubb").
After that I open the terminal (cmd.exe), switch to the directory and type test.sh 2>> log.txt.
Another window opens with "/usr/bin/bash --login -i \test.sh" in the title bar, shows me "bash: blablubb: command not found" and then closes immediately.
I want to save that output because the bash-window just opens for a split second. Every google search brings me to websites talking about redirecting the output and that Stream2 ist STDERR and therefore I should use test.sh 2>> log.txt or something smiliar that takes care of the STDERR stream.
If I try the same with a test.sh file and the content:
#!/bin/bash
echo hi there
I get the output in the briefly open bash-window:
bash: #!/bin/bash: No such file or directory
hi there
But the log.txt file is empty.
If I only have echo hi therein the test.sh file I get bash: echo: command not found in the bash-window.
The log.txt also empty.
If I type the following directly in the terminal, the output is written in the log.txt:
echo hi > log.txt 2>&1
If I type directly in the terminal:
echdo hi > log.txt 2>&1
I get 'Der Befehl "echdo" ist entweder falsch geschrieben oder konnte nicht gefunden werden.' in the log.txt file.
So I guess the redirecting of the output works fine until I use test.sh.
I know that .sh files are something from the unix world and that the problem might lie there but I don't know why I can not redirect the output briefly shown in the bash-console to a text file.
The 2>> redirection syntax only works if the command line containing that syntax is interpreted by bash. So it won't work from the Windows command prompt, even if the program you are running happens to be written in bash. By the time bash is running, it's too late; it gets the arguments as they were interpreted by CMD or whatever your Windows command interpreter is. (In this case, I'm guessing that means the shell script will find it has a command line argument [$1] with the value "2".)
If you open up a bash window (or just type bash in the command one) and then type the test.sh 2>>log.txt command line in that shell, it will put the error message in the file as you expect.
I think you could also do it in one step by typing bash -c "test.sh 2>>log.txt" at the Windows command prompt, but I'm not sure; Windows quoting is different than *nix quoting, and that may wind up passing literal quotation marks to bash, which won't work.
Note that CMD does have the 2>> syntax as well, and if you try to run a nonexistent windows command with 2>>errlog.txt, the "is not recognized" error message goes to the file. I think the problem comes from the fact that CMD and bash disagree on what "standard error" means, so redirecting the error output from Windows doesn't catch the error output by bash. But that's just speculation; I don't have a bash-on-Windows setup handy to test.
It would help to know if you are running Windows Subsystem for Linux (Beta). Or if you are doing something else. I'm assuming this is what you are doing on windows 10.
If this is the case are you using bash to run the script?
Are you using win-bash?
If it is win-bash I'm not very familiar and would recommend Windows Subsystem for Linux (Beta) for reasons like this. win-bash, while cool, might not be compatible with redirection operators like 2>>.
You have stdout and stderr, by default (if you don't specify) the >> (or append) will only append standard output into the txt file.
If you use 2 it will append the standard error into the txt file. Example: test.sh 2>> log.txt
This could be better described at this site.
To get exactly the command for append both stdout and stderr, go to this page.
Please tell me if this doesn't answer your question. Also, it could be more valuable to attempt a search for this answer first and explain why your search found nothing or give more extensive clarification as to what the problem is. I love answering questions and helping, but creating a new forum page for what might be an easy answer may be ineffective. I've had a bunch of fun with your question. I hope that I've helped.
That's makes a lot of sense. Thanks Mark!
Taking what mark says into account I would get Windows Subsystem for Linux (Beta). There are instructions here. Then run your script from there.
I can't figure out how to get output from shell script back to rtorrent after command has been executed.
Is it possible to return back output from exeternal command back to rtorrent session?
I use rtorrent scripting interface to auto execute shell command after torrent is finished
event line in .rtorrent.rc looks like this:
system.method.set_key = event.download.finished,mycustomcommand,"execute=~/myshellscript.sh"
myshellscript.sh file looks like this
#!/bin/sh
echo "Torrent finished!"
Is there a way to do this?
I'm not sure what you're searching for, but I found this on rtorrent's wiki site:
execute_capture_nothrow={command,arg1,arg2,...}
This will execute the external command with arguments arg1,arg2,.... It will return the
stdout output of the command.
system.method.set_key = event.download.finished,mycustomcommand,print="$execute_capture=/path/to/script"
should work, at least
print="$execute_capture=/path/to/script"
works when you do it inside rtorrent. If you want to store the output then intstead of print use d.custom1.set= if that helps.
You forgot to add parameters to the rtorrent.rc itself and also the bash script is incomplete according to me.
.rtorrent.rc line should have
method.set_key = event.download.finished,whatever,"execute2={/path/myscript.sh,$d.name=,$d.base_path=,$d.hash=}"
bash script
#!/bin/bash
TORRENT_NAME=1
TORRENT_PATH=2
TORRENT_HASH=3
touch "$1" Finished download!
exit
this will create touch file telling you particular file has finished downloading.
There are a lot of tips (and warnings) on here for obfuscating various items within scripts.
I'm not trying to hide a password, I'm just wondering if I can obfuscate an actuall command within the script to defeat the casual user/grepper.
Background: We have a piece of software that helps manage machines within the environment. These machines are owned by the enterprise. The users sometimes get it in their heads that this computer is theirs and they don't want "The Man" looking over their shoulders.
I've developed a little something that will check to see if a certain process is running, and if not, clone it up and replace.
Again, the purpose of this is not to defeat anyone other than the casual user.
It was suggested that one could echo an octal value (the 'obfuscated' command) and use it as a variable within the script. e.g.:
strongBad=`echo "\0150\0157\0163\0164\0156\0141\0155\0145"`
I could then use $strongBad within the shell script to slyly call the commands that I wanted to call with arguments?
/bin/$strongBad -doThatThingYouDo -DoEEET
Is there any truth to this? So far it's worked via command line directly into shell (using the -e flag with echo) but not so much within the script. I'm getting unexpected output, perhaps the way I'm using it?
As a test, try this in the command line:
strongBad=`echo -e "\0167\0150\0157"`
And then
$strongBad
You should get the same output as "who".
EDIT
Upon further review, the addition of the path to the echo command in the variable is breaking it. Perhaps that's the source of my issue.
You can do a rotate 13 on any command you want hidden beforehand, then just have the the obfuscated command in the shell script.
This little bash script:
#!/bin/bash
function rot13 {
echo "$#" | tr '[a-m][n-z][A-M][N-Z]' '[n-z][a-m][N-Z][A-M]'
}
rot13 echo hello, world!
`rot13 rpub uryyb, jbeyq!`
Produces:
rpub uryyb, jbeyq!
hello, world!
I have an app installed on solaris which have its own specific commands,normally I have run below commands one by one in terminal:
eaw DDBSC1
(then the prompt will change to <)
< rldep:Cell=all;
I am looking to a script to put it in bash file and simply run it,
I have tried "expect" but it seems the bash script is getting stocked in "eaw DDBSC1" line and is not executing my second line,
Can anyone help?
Use a bash 'here document'. The commands following << ! will be interpreted by the shell until the following !end string.
eaw DDBSC1 << !end
rldep:Cell=all;
!end
I have a bash script and I want to use ncftp to do something. if I have this:
#!/bin/sh
HOST='my_IP_FTP_HOST'
USER='username'
PASSWD='password'
ncftp -u $USER -p $PASSWD $HOST <<END_SCRIPT
pwd
quit
END_SCRIPT
I get this error:
Syntax error in parameters or arguments
I don't understand why.
If I give it only the value and not the variables it works...
if I launch
$ sh -x script.sh
I get:
+ HOST=$'xxx.x.xx.xx\r'
+ USER=$'username\r'
+ PASSWD=$'password\r'
+ ncftp -u $'username\r' -p $'password\r' $'xxx.x.xx.xx\r'
NcFTP 3.2.1 (Jul 29, 2007) by Mike Gleason (http://www.NcFTP.com/contact/).
Welcome to FTP server
Syntax error in parameters or arguments
hmmm.... \r creates problems sure.
Are you editing this file on Microsoft Windows? It doesn't works because the original file uses Windows carriage returns, which are passed to variables and then to ncftp, which then halts.
Fix it by using another text editor, or by using dos2unix. Ideally you'd first use dos2unix once and then change the text editor.
Alternatively (but really, really not recommended) you could just parse the variables and remove the extra \r, like below, especially when the problem arises at some input reading, which doesn't seems to be the case here.
HOST=${HOST%\\r}
USER=${USER%\\r}
PASSWD=${PASSWD%\\r}
Take care when copying text from Windows, or when editing without appropriate software.