Newly generated function will become the callback of the fs.stat() method. The generate_callback will create a new function and will return that function. JavaScript will call the generate_callback() function with the current value of file. So every time we run fs.stat(), before fs.stat() is actually executed, We will call a function named generate_callback() that In this solution, instead of adding a hard-coded callback function So we need to find a way to pass the file parameter to the internal callback. Then suddenly we cannot rely on the order of callback calls to be the same as the order If the operation was more complex, and especially if there can be internal callbacks as well, This might work as we can expect the events to be handled one after the other, but In this particular case of calling stat on items in a single directory, Then we need to rely on the order of calls. So if we want to combine the name of the file and the result of the fs.stat() call Variable is just a simple global variable (from the point of view of theĬallback) and by the time the first callback was executed, the file variable wasĪlready assigned the last entry in the directory. Variable was the same for every callback. The sizes seem to match the filenames, because these were printed in the same orderĪs we called fs.stat(), but for some reason the content of the file rw-r-r- 1 gabor staff 27 Jan 29 14:54 raw_command_line_arguments.js rw-r-r- 1 gabor staff 18 Jan 31 08:24 process_exit.js rw-r-r- 1 gabor staff 151 Jan 29 14:26 non-blocking-read-file.js rw-r-r- 1 gabor staff 270 Jan 27 12:34 node_hello_world_port.js rw-r-r- 1 gabor staff 243 Jan 27 12:34 node_hello_world.js rw-r-r- 1 gabor staff 97 Jan 29 14:26 blocking-read-file.js The debugging printout printed the names as expected, but then inside theĬallback of fs.stat() we keep printing out the same filename. Start: /home/gabor/work//examples//stats.js ![]() Start: /home/gabor/work//examples//read_dir.js Start: /home/gabor/work//examples//process_exit.js Start: /home/gabor/work//examples//non-blocking-read-file.js ![]() Start: /home/gabor/work//examples//node_hello_world_port.js Start: /home/gabor/work//examples//node_hello_world.js Start: /home/gabor/work//examples//blocking-read-file.js $ node examples/node/list_dir_direct.js ~/work//examples/ In that function we print out the name of the file - this time as part of the result,Īnd then print out the size of the thing. That method in turn accepts a callback function. Of the current file (after we have attached it to the full path of the directory) mostlyįor debugging purposes, and we call the fs.stat. In that for-loop, on every iteration we print out the name Inside the callback of the readdir method, Now that we know how to get the list of entries in a directory, and that we already know how to $ node examples/node/read_dir.js ~/work//examples/ which point to the current directory and. The listing will contain everything, except of. The list with a for loop and do something with each item. If everything went well, then the second parameter will be an array withĪll the items (files, directories, symbolic links, etc.) that were found in the directory.Īt that point, inside the callback function we can either just print the whole array - if we just want to enjoy our success or we can iterate over ![]() If there was an error then the first parameter will hold that information. The second one is a callback that will be called when the the operation has finished. The first one is the error object in case there was an error. It will read the content of the directory into memory and when done it will execute the callback with 2 parameters. That gets a path and a callback function as parameters. Here we use the readdir method of the fs class, Then you already know the first part of the script. If you have read the article about the fetching system information for a single file (Without recursion.)Ĭonsole.log("Usage: " + _filename + " path/to/directory") This script will accept (and even require) a path to a directory on the command line,Īnd then it will list the content of the directory. So if we only need to generated all the entries in a directory and then call fs.stat We already know how to get information from the inode of a file or directory,
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |