backticks

问题 I have a trouble with the following very simple and small Perl script on Windows platform. use strict; use warnings; use threads; use threads::shared; my $print_mut : shared; my $run_mut : shared; my $counter : shared; $counter = 30; ############################################################### sub _print($) { lock($print_mut); my $str = shift; my $id = threads->tid(); print "[Thread_$id] $str"; return; } ############################################################### sub _get_number() {

问题 I want to lookup some data of running processes, actually I'm searching for the scratch directory to a corresponding job-ID. I managed to do that manually by the following commands (assuming the job-ID is 12345): find ~ -name '12345.out' This finds the output file according to the job: /home/username/somefolder/12345.out The scratch directory is written to a file named .scrdir in that folder, so cd | cat /home/username/somefolder/.scrdir brings me where I want. I now want to combine that to a

问题 This is my data class created using a Kotlin data class creator Plugin. data class ResponseHealthInisghts( val `data`: List<Data>, val message: String, val statusCode: Int ) This code gets work even if I remove the backticks, I wonder if it's for Java interoperability. But this variable is not a keyword but also it has backticks. why? Based on Why does this Kotlin method have enclosing backticks? this question is is a keyword for both Java and Kotlin but data is not. 回答1: You can use

问题 From the Bash FAQ: Backslashes (\) inside backticks are handled in a non-obvious manner: $ echo "`echo \\a`" "$(echo \\a)" a \a $ echo "`echo \\\\a`" "$(echo \\\\a)" \a \\a But the FAQ does not break down the parsing rules that lead to this difference. The only relevant quote from man bash I found was: When the old-style backquote form of substitution is used, backslash retains its literal meaning except when followed by $, `, or . The "$(echo \\a)" and "$(echo \\\\a)" cases are easy enough:

问题 If I have this perl app: print `someshellscript.sh`; that prints bunch of stuff and takes a long time to complete, how can I print that output in the middle of execution of the shell script? Looks like Perl will only print the someshellscript.sh result when it completes, is there a way to make output flush in the middle of execution? 回答1: What you probably want to do is something like this: open(F, "someshellscript.sh|"); while (<F>) { print; } close(F); This runs someshellscript.sh and opens

问题 If I have this perl app: print `someshellscript.sh`; that prints bunch of stuff and takes a long time to complete, how can I print that output in the middle of execution of the shell script? Looks like Perl will only print the someshellscript.sh result when it completes, is there a way to make output flush in the middle of execution? 回答1: What you probably want to do is something like this: open(F, "someshellscript.sh|"); while (<F>) { print; } close(F); This runs someshellscript.sh and opens

问题 If I have a variable in backticks is it expanded in the shell or in the subshell? For example: FOO=BAR BAZ=`[[ $FOO == BAR ]] && echo 1 || echo 0` Is it defined when $FOO is expanded? For example does the subshell see this: [[ $FOO == BAR ]] && echo 1 || echo 0 or this: [[ BAR == BAR ]] && echo 1 || echo 0 回答1: (You should really use $(...) instead of backticks. But the principle is the same.) The command to be executed in the subshell consists of the literal characters inside the command

问题 I'm currently working on a Rails application that serves as an Updater for another Rails application. I have the update process working, Download new release zip Extract to proper location Sync Assets Bundle install Precompile Assets Start server with - bundle exec rails server I'm having an issue with the last step. When I run: Dir.chdir('../other-project') `bundle exec rails server -d -p 3000` from the updater app it seems to be pulling from the updaters bundle and not the new application

问题 I'd like to unit test a Perl program of mine that is using backticks. Is there a way to mock the backticks so that they would do something different from executing the external command? Another question shows what I need, but in Ruby. Unfortunately, I cannot choose to use Ruby for this project, nor do I want to avoid the backticks. 回答1: You can * mock the built-in readpipe function. Perl will call your mock function when it encounters a backticks or qx expression. BEGIN { *CORE::GLOBAL:

问题 Perl supports three ways (that I know of) of running external programs: system : system PROGRAM LIST as in: system "abc"; backticks as in: `abc`; running it through a pipe as in: open ABC, "abc|"; What are the differences between them? Here's what I know: You can use backticks and pipes to get the output of the command easily. that's it (more in future edits?) 回答1: system(): runs command and returns command's exit status backticks: runs command and returns the command's output pipes : runs