scope

问题 The UNIX "/usr/bin/script" command will create a running transcript of your shell session (see "man script" for more info). However, when inside a script instance, it seems to forget the parent shell's env vars, aliases, etc. The following example demonstrates how the "ll" alias I define is ignored inside "script": zsh> mkdir temp zsh> cd temp zsh> alias "ll=ls -alF" zsh> ll total 24 drwxr-xr-x 2 me mygroup 4096 Feb 18 13:32 ./ drwxr-xr-x 28 me mygroup 8192 Feb 18 13:32 ../ zsh> script a.out

问题 The UNIX "/usr/bin/script" command will create a running transcript of your shell session (see "man script" for more info). However, when inside a script instance, it seems to forget the parent shell's env vars, aliases, etc. The following example demonstrates how the "ll" alias I define is ignored inside "script": zsh> mkdir temp zsh> cd temp zsh> alias "ll=ls -alF" zsh> ll total 24 drwxr-xr-x 2 me mygroup 4096 Feb 18 13:32 ./ drwxr-xr-x 28 me mygroup 8192 Feb 18 13:32 ../ zsh> script a.out

问题 Working on a NodeJS project, I came a across this very unexpected behaviour that I can't figure a way around - it seems like a bug to me, but perhaps I'm simply misunderstanding how NodeJS modules operate. I've reduced it into a testcase as follows: mod.js module exports.process = function(obj) { obj.two = 'two'; }; test.js file var testObj = {one: 'one'}; console.log(['Before:', testObj]); var cachedObj = testObj; require('./mod').process(cachedObj); console.log(['After:', testObj]); Then

问题 Working on a NodeJS project, I came a across this very unexpected behaviour that I can't figure a way around - it seems like a bug to me, but perhaps I'm simply misunderstanding how NodeJS modules operate. I've reduced it into a testcase as follows: mod.js module exports.process = function(obj) { obj.two = 'two'; }; test.js file var testObj = {one: 'one'}; console.log(['Before:', testObj]); var cachedObj = testObj; require('./mod').process(cachedObj); console.log(['After:', testObj]); Then

问题 I'd like to specify functions in a flexible way. How can I make sure that the environment of a given function does not change when I create another function just after it. To illustrate, this works properly: make.fn2 <- function(a, b) { fn2 <- function(x) { return( x + a + b ) } return( fn2 ) } a <- 2; b <- 3 fn2.1 <- make.fn2(a, b) fn2.1(3) # 8 fn2.1(4) # 9 a <- 4 fn2.2 <- make.fn2(a, b) fn2.2(3) # 10 fn2.1(3) # 8 This does not make.fn2 <- function(a, b) { fn2 <- function(x) { return( x + a

问题 I am trying to use get in series of function calls, but the lookup of the object names seems to skip environments. For example: foo <- 1 # variable in .GlobalEnv getter <- function(x) {get(x)} getter("foo") # returns 1, which is expected f1 <- function() { foo <- 2 # local variable in the function scope getter("foo") } f1() # still returns 1, would've expected to return 2 Why is it that calling f1 returns the foo in the global environment and not the foo in the calling function's environment?

问题 This question is "cousin" of this one involving Android. But here we are in Tomcat environment . If in my webapp I set a property with System.setProperty("property_name", "property_value"); , which scope will it be applied to? all JVM in this machine all Tomcat webapps only the webapp that executes the instruction only the thread that executes the instruction something else... Many thanks! 回答1: A system property has a JVM scope. The property will thus be modified (and available) in the whole

问题 This question is "cousin" of this one involving Android. But here we are in Tomcat environment . If in my webapp I set a property with System.setProperty("property_name", "property_value"); , which scope will it be applied to? all JVM in this machine all Tomcat webapps only the webapp that executes the instruction only the thread that executes the instruction something else... Many thanks! 回答1: A system property has a JVM scope. The property will thus be modified (and available) in the whole

问题 var display_welcome = function(){ var fb_login_button = jQuery('#fb_login_button'); var fb_welcome = jQuery('#fb_welcome'); var name = ''; FB.api('/me',function(response){ console.log(response); name = response.first_name; }); fb_login_button.css('display', 'none'); fb_welcome.html('<span>Welcome, ' + name + '</span>'); fb_welcome.css('display', 'block'); }; This function is called when a user logs into Facebook from a website. The goal is to display a welcome message to the user with the

问题 Following are my files and output. All I want to do is get Value of x after func1() as 20 . I have already referred to this answer. I want to know why this do not work? Is it necessary to use import globalVar instead of from globalVar import * globalVar.py #globalVar.py x=10 fun1.py from globalVar import * def func1(): global x x=20 print("X in fun1",x) main.py from fun1 import * from globalVar import * print("X before fun1=",x) func1() print("X after fun1=",x) Output: X before fun1= 10 X in