{"id":1269,"date":"2009-04-20T05:13:55","date_gmt":"2009-04-20T12:13:55","guid":{"rendered":"http:\/\/www.gubatron.com\/blog\/?p=1269"},"modified":"2009-04-20T05:13:55","modified_gmt":"2009-04-20T12:13:55","slug":"how-to-make-a-quick-dirty-hexviewer-updated","status":"publish","type":"post","link":"https:\/\/www.gubatron.com\/blog\/how-to-make-a-quick-dirty-hexviewer-updated\/","title":{"rendered":"How to make a Quick & Dirty HexViewer – Updated"},"content":{"rendered":"

After I received comments from ispak on Flickr<\/a> I made a few fixes.<\/p>\n

ispak pointed out that it was a bad idea reading one byte at the time, also I had a gay ass try\/catch that didn’t catch any exception :p<\/p>\n

So now I read 16 byte chunks, and I also take care of the file ending. The previous version used to print the file ending with a bunch of null bytes. Now it stops reading at the end, and formats the output accordingly.<\/p>\n

Here’s the new source:<\/p>\n

[java]
\n\/\/HexViewer.java
\nimport java.io.*;<\/p>\n

public final class HexViewer {
\n public final static void printFile(String filePath) {
\n try {
\n File f = new File(filePath);
\n BufferedInputStream bis =
\n new BufferedInputStream(new FileInputStream(f));<\/p>\n

byte[] chunk = null;
\n int readStatus = 0;
\n while (true) {
\n chunk = new byte[16];
\n readStatus = bis.read(chunk, 0, 16);
\n char[] line = new char[16];<\/p>\n

if (readStatus == -1)
\n break;<\/p>\n

for (byte i=0; i < readStatus; i++) {
\n int readByte = (chunk[i] < 0) ? (-1 * (int) chunk[i]) : chunk[i];
\n String paddingZero = (readByte < 16) ? "0" : "";
\n System.out.print(paddingZero + Integer.toHexString(readByte).toUpperCase() + " ");
\n line[i] = (readByte >= 33 && readByte <= 126) ? (char) readByte : ‘.’;
\n }<\/p>\n

\/\/We add some padding to print the text line right below the one above.
\n String padding = new String();
\n if (readStatus < 16) {
\n for (byte i=0; i < 16-readStatus; i++) {
\n padding += " ";
\n }
\n }<\/p>\n

System.out.println(padding + new String(line));
\n }
\n } catch (Exception e1) { e1.printStackTrace(); }
\n }<\/p>\n

public final static void main(String[] args) {
\n if (args.length == 0)
\n return;<\/p>\n

printFile(args[0]);
\n }
\n}
\n[\/java]<\/p>\n

\"HexViewer<\/a><\/p>\n

And see how it now handles file endings when the file size is not a multiple of 16 :p<\/p>\n

\"Picture<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

After I received comments from ispak on Flickr I made a few fixes. ispak pointed out that it was a bad idea reading one byte at the time, also I had a gay ass try\/catch that didn’t catch any exception :p So now I read 16 byte chunks, and I also take care of the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[15,43],"tags":[1437,584],"class_list":["post-1269","post","type-post","status-publish","format-standard","hentry","category-code","category-linux","tag-code","tag-java-hex-hexviewer-programming"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p5Unzf-kt","jetpack-related-posts":[{"id":1928,"url":"https:\/\/www.gubatron.com\/blog\/droid-vs-nexus-1-who-can-calculate-md5-faster\/","url_meta":{"origin":1269,"position":0},"title":"Droid vs Nexus 1: Who can calculate MD5 faster?","author":"gubatron","date":"May 21, 2010","format":false,"excerpt":"Nexus 1 indeed. 17 files get their MD5 calculated on the Droid and 17 files get their MD5 hash calculated on the Nexus 1 Nexus 1 pwns. Here's the code in case you're curious. [java] public void onClick(View v) { _logTextView.setText(\"MD5 Benchmark on \" + Build.DEVICE + \"nn\"); if (GlobalVariables.APP_CONTEXT\u2026","rel":"","context":"In "Android"","block_context":{"text":"Android","link":"https:\/\/www.gubatron.com\/blog\/category\/android\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1252,"url":"https:\/\/www.gubatron.com\/blog\/how-to-make-your-own-quick-dirty-hex-file-viewer-in-java\/","url_meta":{"origin":1269,"position":1},"title":"How to make your own Quick & Dirty Hex File Viewer in Java","author":"gubatron","date":"April 18, 2009","format":false,"excerpt":"Update: You might want to read this new version of the code instead. Thanks ispak I was playing with a hex editor recently and then I thought it would be pretty easy to make a program to output what you see on a text editor. Here's a quick & dirty\u2026","rel":"","context":"In "Code"","block_context":{"text":"Code","link":"https:\/\/www.gubatron.com\/blog\/category\/code\/"},"img":{"alt_text":"Same file on HexEdit","src":"https:\/\/i0.wp.com\/farm4.static.flickr.com\/3634\/3452718760_995edb5218_o.png?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/farm4.static.flickr.com\/3634\/3452718760_995edb5218_o.png?resize=350%2C200 1x, https:\/\/i0.wp.com\/farm4.static.flickr.com\/3634\/3452718760_995edb5218_o.png?resize=525%2C300 1.5x"},"classes":[]},{"id":2063,"url":"https:\/\/www.gubatron.com\/blog\/android-programming-how-to-obtain-the-wifis-corresponding-networkinterface\/","url_meta":{"origin":1269,"position":2},"title":"Android: How to obtain the WiFi’s corresponding NetworkInterface","author":"gubatron","date":"September 19, 2010","format":false,"excerpt":"Let's say for some odd reason in the world you do need to get the corresponding NetworkInterface object of the Wifi on your android, in my case I needed to have my WiFi device send multicast packets, and I wanted my MulticastSocket to only send packets through the WiFi device\u2026","rel":"","context":"In "Android"","block_context":{"text":"Android","link":"https:\/\/www.gubatron.com\/blog\/category\/android\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":4000,"url":"https:\/\/www.gubatron.com\/blog\/what-is-the-rust-equivalent-to-javas-printwriter\/","url_meta":{"origin":1269,"position":3},"title":"What is the Rust equivalent to Java’s PrintWriter?","author":"gubatron","date":"December 21, 2022","format":false,"excerpt":"In Rust, the equivalent of Java's PrintWriter is the std::io::Write trait, which is implemented by a number of types that can be used to write data to an output stream, such as a file or a network socket. To use Write to write text to an output stream, you can\u2026","rel":"","context":"In "Code"","block_context":{"text":"Code","link":"https:\/\/www.gubatron.com\/blog\/category\/code\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.gubatron.com\/blog\/wp-content\/uploads\/2022\/12\/progress_image_100_7fdc7b72-6c19-42f5-affe-d055d02d6f8e.webp?fit=1024%2C1024&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.gubatron.com\/blog\/wp-content\/uploads\/2022\/12\/progress_image_100_7fdc7b72-6c19-42f5-affe-d055d02d6f8e.webp?fit=1024%2C1024&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.gubatron.com\/blog\/wp-content\/uploads\/2022\/12\/progress_image_100_7fdc7b72-6c19-42f5-affe-d055d02d6f8e.webp?fit=1024%2C1024&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.gubatron.com\/blog\/wp-content\/uploads\/2022\/12\/progress_image_100_7fdc7b72-6c19-42f5-affe-d055d02d6f8e.webp?fit=1024%2C1024&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":3616,"url":"https:\/\/www.gubatron.com\/blog\/codejava-argb_8888-pixel-abstraction\/","url_meta":{"origin":1269,"position":4},"title":"[CODE\/JAVA] ARGB_8888 Pixel Abstraction","author":"gubatron","date":"December 4, 2016","format":false,"excerpt":"This is one of the ways you can decode Pixel colors out of the integers you get from Android Pixels. ARGB_8888, stands for Alpha, Reg, Green, Blue. The 8's stand for the number of bits per channel. In Android, signed int's are used to represent pixel's alpha\/color information. Since Android's\u2026","rel":"","context":"In "Code"","block_context":{"text":"Code","link":"https:\/\/www.gubatron.com\/blog\/category\/code\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":980,"url":"https:\/\/www.gubatron.com\/blog\/javareflection-notes-invoking-a-static-main-method-from-a-dinamically-loaded-class\/","url_meta":{"origin":1269,"position":5},"title":"Java\/Reflection notes: Invoking a static main() method from a dinamically loaded class.","author":"gubatron","date":"November 22, 2008","format":false,"excerpt":"Maybe for some wild reason, your Java application will need to execute a pre launcher that won't know about the Main class it's supposed to invoke until it's being executed. 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