I am using a function that I found in YADR which should insert the output of the last command.
# Use Ctrl-x,Ctrl-l to get the output of the last command
zmodload -i zsh/parameter
insert-last-command-output() {
LBUFFER+="$(eval $history[$((HISTCMD-1))])"
}
zle -N insert-last-command-output
bindkey "^X^L" insert-last-command-output
For some reason, it does not seem to work by pressing ctrl-x ctrl-l but running
echo $(eval $history[$((HISTCMD-1))])
command on the terminal does produce the output of the last command.
Running bindkey -M viins shows "^X^L" insert-last-command-output
as one of the entries. Therefore, the function is registered.
I don't really understand how the function works. I think that the variable LBUFFER holds the output of all last commands but when I echo $LBUFFER, it returns the function code.
Can anyone help me get this working?
I finally found a solution.
I had been trying to use the shortcut inside tmux which did not work. However, outside tmux, everything worked. It turns out that tmux will not allow a shortcut with two keys. I changed the shortcut to just alt-L and everything works.
Related
I am trying to update a simple JSON file (consists of one object with several key/value pairs) and I am using the same command yet getting different results (sometimes even having the whole json wiped with the 2nd command). The command I am trying is:
cat ~/Desktop/config.json | jq '.Option = "klay 10"' | tee ~/Desktop/config.json
This command perfectly replaces the value of the minerOptions key with "klay 10", my intended output.
Then, I try to run the same process on the newly updated file (just value is changed for that one key) and only get interactive terminal with no result. ps unfortunately isn't helpful in showing what's going on. This is what I do after getting that first command to perfectly change the value of the key:
cat ~/Desktop/config.json | jq ‘.othOptions = "-epool etc-eu1.nanopool.org:14324 -ewal 0xc63c1e59c54ca935bd491ac68fe9a7f1139bdbc0 -mode 1"' | tee ~/Desktop/config.json
which I would have expected would replace the othOptions key value with the assigned result, just as the last did. I tried directly sending the stdout to the file, but no result there either. I even tried piping one more time and creating a temp file and then moving it to change to original, all of these, as opposed to the same identical command, just return > and absolutely zero output; when I quit the process, it is the same value as before, not the new one.
What am I missing here that is causing the same command with just different inputs (the key in second comes right after first and has identical structure, it's not creating an object or anything, just key-val pair like first. I thought it could be tee but any other implementation like a passing of stdout to file produces the same constant > waiting for a command, no user.
I genuinely looked everywhere I could online for why this could be happening before resorting to SE, it's giving me such a headache for what I thought should be simple.
As #GordonDavisson pointed out, using tee to overwrite the input file is a (well-known - see e.g. the jq FAQ) recipe for disaster. If you absolutely positively want to overwrite the file unconditionally, then you might want to consider using sponge, as in
jq ... config.json | sponge config.json
or more safely:
cp -p config.json config.json.bak && jq ... config.json | sponge config.json
For further details about this and other options, search for ‘sponge’ in the FAQ.
I'm new using Tcl and I have the following script:
proc prepare_xml {pdb_id} {
set filename [exec wget ftp://ftp.ebi.ac.uk/pub/databases/msd/sifts/xml/$pdb_id.xml.gz]
set filename_unzip [exec gunzip "$pdb_id.xml.gz"]
set ready_xml [exec sed -i "/entry /c\<entry>" "$pdb_id.xml"]
return $ready_xml
}
The expected output is the file "filename" uncompress and modified. However, when I execute it the first time, it only downloads the file and it does not uncompress it. If I execute it for a second time, I obtained the expected output and a second copy of the original downloaded file.
Can anyone help me with this? I've tried with after and vwait commands but it doesn't work.
Thank you :)
It's hard to say for sure as you're not describing whether any errors are thrown (that'd be the only reason for the code to not run to completion), but I'd expect something like this to be the right approach:
proc prepare_xml {pdb_id} {
# Double quotes on next line just because of Stack Overflow highlighter
set url "ftp://ftp.ebi.ac.uk/pub/databases/msd/sifts/xml/$pdb_id.xml.gz"
set file $pdb_id.xml
append sedcode {/entry /} "c\\\n" {<entry>}
exec wget -q -O - $url | gunzip -c | sed $sedcode > $file
return $file
}
Firstly, I'm keeping complicated bits in (local) variables to stop the exec line from getting too long. Secondly, I've put all the subprocesses together in the one pipeline. Thirdly, I'm using -q and -O - with wget, and -c with gunzip; look up what they do if you don't understand them. Fourthly, I've put the scriptlet for sed in braces where possible to stop there from being trouble with backslashes, but I've used append and a non-backslashed section to make the pattern because the syntax of c in sed is downright weird (it needs a backslash-newline sequence immediately after on at least some platforms…)
I'd actually use native Tcl code to extract and transform the data if I was doing it for me, but that's a rather larger change.
I am trying to write a GNU make call function (example below) which has multiple shell commands to execute, such that it can be called with different arguments.
shell_commands = $(shell echo $(1); ls -ltr $(2))
try:
$(call shell_commands,$(FILE1),$(FILE2))
1) Is above the correct way to write a call function with multiple commands? By using a semi-colon to separate them? To make it readable, I write my targets as shown below. Is there a similar way to write a call function?
shell_commands:
echo $(1)
ls -ltr $(2)
2) I get this error from make when I execute make -B try. It looks like it is trying to execute /home/user/file1. But why?
make: execvp: /home/user/file1: Permission denied
make: *** [try] Error 127
3) Is it possible to pass variable number of parameters to a call function? Like pass in just the second parameter and not the first one.
$(call shell_commands,,$(FILE2))
I tried google-ing, searching on SO, and looking on gnu.org but I did not get any solutions. Will appreciate any answers or pointers to any resources which document call function with multiple optional arguments and commands.
Question 1: No, this is not right. The shell make function should NEVER be used inside a recipe: the recipe is already running in the shell, so why would you run another shell? It's just confusing. Second, it's generally recommended to use && between multiple commands in a recipe, so that if the first command fails the entire command will immediately fail, rather than continuing on and perhaps succeeding. Of course, that is not always correct either, it depends on what you're trying to do.
Question 2: This happens because the shell make function is like backticks in the shell: it expands to the output printed by the shell command it runs. Your shell command that make runs is:
echo $(1); ls -ltr $(2)
(where, one assumes, $1 expands to /home/user/file1) which prints the string /home/user/file1. After the expansion, that string is substituted into the recipe and make tries to run that recipe, giving the error you see above.
You want this, most likely:
shell_commands = echo $(1) && ls -ltr $(2)
try:
$(call shell_commands,$(FILE1),$(FILE2))
Now the call expands to the actual text, not an invocation of make's shell function, and then that text is run as the recipe.
Question 3: Sure, just using empty parameters means that the variable $1 (in this case) expands to the empty string.
Hello and thank you for any help you can provide
I have my Apache2 web server set up so that when I go to a specific link, it will run and display the output of a shell script stored on my server. I need to output the results of an SVN command (svn log). If I simply put the command 'svn log -q' (-q for quiet), I get the output of:
(of course not blurred), and with exactly 72 dashes in between each line. I need to be able to take these dashes, and turn them into an html line break, like so:
Basically I need the shell script to take the output of the 'svn log -q' command, search and replace every chunk of 72 dashes with an html line break, and then echo the output.
Is this at all possible?
I'm somewhat a noob at shell scripting, so please excuse any mess-ups.
Thank you so much for your help.
svn log -q | sed -e 's,-{72},<br/>,'
If you want to write it in the script this might help:
${string//substring/replacement}
Replace all matches of $substring with $replacement.
stringZ=abcABC123ABCabc
echo ${stringZ/abc/xyz} # xyzABC123ABCabc
# Replaces first match of 'abc' with 'xyz'.
echo ${stringZ//abc/xyz} # xyzABC123ABCxyz
# Replaces all matches of 'abc' with # 'xyz'.
I've tried just about EVERYTHING. I've tried exec. I've tried open with a pipe. I've tried expect's spawn command. I've even tried creating scripts that launch the application. None of this works. It should be something so freaking simple but it isn't. Basically I want something that executes "./myapp &". I don't want the parent app to wait for any input. I don't want the parent app to kill the child when it's closed. Nor do I want the closure of the child to affect the parent.
I've spent 4 hours trying to do this with no dice.
EDIT 4: I have produced a small test case. Actually. I know think the bug is related to a shell script called from tcl not recognizing it's finished and wanting more input. But oddly, the script does run and the following tcl commands are still executed.
Create a file called "data.dat"
9.2877556131E+03 1.2512862771E-15 1.5337670739E-18
9.2910873127E+03 1.2439911921E-15 1.5339531650E-18
9.2944190123E+03 1.2253566905E-15 1.5354833054E-18
9.2977507119E+03 1.2115157273E-15 1.6142496743E-18
9.3010824115E+03 1.2080944425E-15 1.7533261348E-18
9.3044141111E+03 1.2076649858E-15 1.8405304542E-18
9.3077458106E+03 1.1904275879E-15 1.8336914953E-18
9.3110775102E+03 1.1790369061E-15 1.8270892064E-18
9.3144092098E+03 1.1620102216E-15 1.8244075829E-18
9.3177409094E+03 1.1178361307E-15 1.8581382655E-18
9.3210726090E+03 1.0969704027E-15 1.8237852087E-18
9.3244043086E+03 1.0721326432E-15 1.7016959482E-18
9.3277360082E+03 1.0699729320E-15 1.6841145916E-18
9.3310677078E+03 1.0266229217E-15 1.7253936877E-18
9.3343994074E+03 9.0875918248E-16 1.6065954292E-18
9.3377311069E+03 7.9157363851E-16 1.5220001484E-18
and then run this tcl file on it
#!/usr/bin/wish
frame .main
button .button -text "Make plot" -command { makeplot }
pack .button
proc makeplot {} {
set data {#!/bin/bash
cat << EOF > plot.gnu
splot "data.dat" using 1:2:3 with points
EOF
}
set fileId [open "plot.csh" "w"]
puts -nonewline $fileId $data
flush $fileId
close $fileId
exec chmod +x ./plot.csh
exec ./plot.csh
exec gnuplot -persist < plot.gnu &
}
The gnuplot plot will not appear until you "foreground" it. I have tried many variations on this (with/without the ampersand). Strangely, I DID get a version of this working under bash.
EDIT 5: I GIVE UP! This test case is now working. It was not just moments ago. I have NO idea what's going on here. This has been one of the hardest bugs to fix in 15 years of programming.
Try exec with & at the end:
exec ./myapp &
Have you tried piping to 'at now'?
./myapp | at now