From e8bbeecc4c154a333e0ac56ac9176243fd056594 Mon Sep 17 00:00:00 2001 From: James M Snell Date: Sat, 26 Dec 2015 21:19:35 -0800 Subject: [PATCH] doc: improvements to debugger.markdown copy General improvements to debugger.markdown PR-URL: https://github.com/nodejs/node/pull/4436 Reviewed-By: Colin Ihrig Reviewed-By: Stephen Belanger Reviewed-By: Minwoo Jung Reviewed-By: Ben Noordhuis --- doc/api/debugger.markdown | 58 +++++++++++++++++++++------------------ 1 file changed, 31 insertions(+), 27 deletions(-) diff --git a/doc/api/debugger.markdown b/doc/api/debugger.markdown index 77671b7a7f75b8..1f9d6703b7e014 100644 --- a/doc/api/debugger.markdown +++ b/doc/api/debugger.markdown @@ -4,9 +4,10 @@ -V8 comes with an extensive debugger which is accessible out-of-process via a -simple [TCP protocol][]. Node.js has a built-in client for this debugger. To -use this, start Node.js with the `debug` argument; a prompt will appear: +Node.js includes a full-featured out-of-process debugging utility accessible +via a simple [TCP-based protocol][] and built-in debugging client. To use it, +start Node.js with the `debug` argument followed by the path to the script to +debug; a prompt will be displayed indicating successful launch of the debugger: % node debug myscript.js < debugger listening on port 5858 @@ -17,11 +18,13 @@ use this, start Node.js with the `debug` argument; a prompt will appear: 3 debugger; debug> -Node.js's debugger client doesn't support the full range of commands, but -simple step and inspection is possible. By putting the statement `debugger;` -into the source code of your script, you will enable a breakpoint. +Node.js's debugger client does not yet support the full range of commands, but +simple step and inspection are possible. -For example, suppose `myscript.js` looked like this: +Inserting the statement `debugger;` into the source code of a script will +enable a breakpoint at that position in the code. + +For example, suppose `myscript.js` is written as: // myscript.js x = 5; @@ -31,7 +34,7 @@ For example, suppose `myscript.js` looked like this: }, 1000); console.log('hello'); -Then once the debugger is run, it will break on line 4. +Once the debugger is run, a breakpoint will occur at line 4: % node debug myscript.js < debugger listening on port 5858 @@ -73,20 +76,20 @@ Then once the debugger is run, it will break on line 4. % -The `repl` command allows you to evaluate code remotely. The `next` command -steps over to the next line. There are a few other commands available and more -to come. Type `help` to see others. +The `repl` command allows code to be evaluated remotely. The `next` command +steps over to the next line. Type `help` to see what other commands are +available. ## Watchers -You can watch expression and variable values while debugging your code. -On every breakpoint each expression from the watchers list will be evaluated -in the current context and displayed just before the breakpoint's source code -listing. +It is possible to watch expression and variable values while debugging. On +every breakpoint, each expression from the watchers list will be evaluated +in the current context and displayed immediately before the breakpoint's +source code listing. -To start watching an expression, type `watch("my_expression")`. `watchers` -prints the active watchers. To remove a watcher, type -`unwatch("my_expression")`. +To begin watching an expression, type `watch('my_expression')`. The command +`watchers` will print the active watchers. To remove a watcher, type +`unwatch('my_expression')`. ## Commands reference @@ -154,19 +157,20 @@ breakpoint) ### Various * `scripts` - List all loaded scripts -* `version` - Display v8's version +* `version` - Display V8's version ## Advanced Usage -The V8 debugger can be enabled and accessed either by starting Node.js with -the `--debug` command-line flag or by signaling an existing Node.js process -with `SIGUSR1`. +An alternative way of enabling and accessing the debugger is to start +Node.js with the `--debug` command-line flag or by signaling an existing +Node.js process with `SIGUSR1`. -Once a process has been set in debug mode with this it can be connected to -with the Node.js debugger. Either connect to the `pid` or the URI to the -debugger. The syntax is: +Once a process has been set in debug mode this way, it can be connected to +using the Node.js debugger by either connecting to the `pid` of the running +process or via URI reference to the listening debugger: * `node debug -p ` - Connects to the process via the `pid` -* `node debug ` - Connects to the process via the URI such as localhost:5858 +* `node debug ` - Connects to the process via the URI such as +localhost:5858 -[TCP protocol]: https://github.com/v8/v8/wiki/Debugging-Protocol +[TCP-based protocol]: https://github.com/v8/v8/wiki/Debugging-Protocol