rot13 in c

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Press button, get ROT13. How @Michael said this char out[alen] is not accepted by the compiler because you can't declare an array size with a non constant value. How true is this observation concerning battle? to my attention. Unicode lookup Text to base64 Zählwerk Enigma Integer encoder Hex & binary Cryptii. ROT13 is typically supported as a built-in feature to newsreading software. Your email address will not be published. ROT13 in Javascript. ** May you share freely, never taking more than you give. Simply pass in a string and get the modified string back. ROT13 to text: ROT13 encoder and decoder. It's fine in short programs like this, but as you hinted that you're fairly new to C++, I wanted to mention that this can be a bad habit to get into. The ROT13 encoding simply shifts every letter by 13 places in the alphabet while leaving non-alpha characters untouched. Where is my implementation of rot13 in JavaScript going wrong? ROT13 cipher refers to the abbreviated form Rotate by 13 places. Use ToCharArray and a char lookup table. ROT13 ("ROTate by 13 places", sometimes hyphenated ROT-13, or lowercase rot13) is a simple Caesar cipher used for obscuring text by replacing each letter with the letter thirteen places down the alphabet. World's simplest ROT13 tool. A shift of thirteen was chosen over other values, such as three as in the original Caesar cipher, because thirteen is the value for which encoding and decoding are equivalent, thereby allowing the convenience of a single command for both. I wrote this code in two languages, C Programming and PHP. ROT13 was in use in the net.jokes newsgroup by the early 1980s. QKL. It has been described as the "Usenet equivalent printing an answer to a quiz upside down" as it provides virtually no cryptographic security. Performs the ROT13 encoding on the string argument and returns the resulting string. your coworkers to find and share information. 261 1 1 gold badge 2 2 silver badges 11 11 bronze badges. Download this app from Microsoft Store for Windows 10, Windows 8.1. C Power of a Number using Pow Function C Programming Code to input two numbers from user and find their power using pow() function. Rot13 is an example of a simple Caesar cipher, where every character in a piece of text is shifted down a fixed number of positions in the alphabet. This transformation cipher shifts letters 13 places in the alphabet. File ext/misc/rot13.c. Applying ROT13 to the transformed file returns the original. Basically, I want to rotate every letter in args[]... c rot13. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. O.K., someone brought an even shorter implementation (46 characters) to Its operation, when executed, is either to perform ROT13 encoding on, or to reverse its input. Upon deciding that XOR sucks, I decided to adapt it to the almighty ROT13! tr is itself actually written in C, and by its inclusion, kinda Just paste your text in the form below, press ROT13 Translate button, and you get ROT13-encoded string. somehow I doubt it. But this code seems to be pretty sluggish: I know there a lot of holes here - could you show me how to fix this? A character will be encoded using the following character 13 positions to replace it. Why do massive stars not undergo a helium flash. What does ROT13 mean? The ROT13 algorithm is a simple encryption algorithm. ROT13 decoder: Decrypt and convert ROT13 to text. The icing on the cake is that the code itself encrypts and decrypts ROT13. If I knock down this building, how many other buildings do I knock down as well? Applying ROT13 to the transformed file returns the original. sorta makes the code much longer. New command only for math mode: problem with \S. A becomes N, B becomes O and so on. It's used on USENET to post material that may be offensive - the reader has to choose to convert it back to plain text. rev 2021.1.8.38287, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide, You might like to learn using a debugger (like. ROT13 is a special case of the popular Caesar cipher. For example, a shift of one would mean all B’s in a text would be replaced with A’s. We have used a simple method of adding and subtracting a key value for encryption and decryption . as Antoine Mathys points and as pointed in my answer, the transform is not correct. What does ROT13 mean? You must use a pointer to the start of the string as argument of the function, because You can't return arrays in C (But you can return pointers ). rot13 /rot ther’teen/ /n.,v./ [Usenet: from `rotate alphabet 13 places’] The simple Caesar-cypher encryption that replaces each English letter with the one 13 places forward or back along the alphabet, so that “The butler did it!” becomes “Gur ohgyre qvq vg!” Most Usenet news reading and posting programs include a rot13 feature. Thanks a lot guys, I solved the problem with this code. rot13 encoder. The coding units used are called the ciphertext and the modal group mentioned is called the alternate ciphertext. But However +1 for the, Added solution for proper ROT13 that would also work for ROT(N). I am trying to learn C and I came across the ROT13 scrambling system used to store some passwords. So I switched to a boolean algebra solution. With this tool, you can encode or decode the given text to and from ROT13 encoding. Applying ROT13 to the transformed file returns the original. Westley's computer program can be ROT13'd or reversed and still compiles correctly. How can a probability density value be used for the likelihood calculation? Applying ROT13 to the transformed file returns the original. Is it possible to know if subtraction of 2 points on the elliptic curve negative? A becomes N, B becomes O and so on. The algorithm … Only an idiot would be fooled by this encoding, but nonetheless the encoding … 3. votes . In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. rot13.c /* rot13 algorithm. Rot13 is an example of a simple Caesar cipher, where every character in a piece of text is shifted down a fixed number of positions in the alphabet. @MichaelSh Your claim that an array's size must be a compile-time constant is only true for C before C99, which introduced variable-length arrays. Brian wrote a piece of C code which would compile either as written, or when encrypted using ROT13. Update More advanced version of the transform that takes care of case when str[i] + 13 > 'z'. :) Well, I'm pretty sure my program complies to the ROT13 rule and I was wondering if any of you dudes would check it out for me and see if it is. Method 1: C++ program to encrypt and decrypt the string using Caesar Cypher Algorithm. void rot13 (char *s) { if (s == NULL) return; int i; for (i = 0; s[i]; i++) { if (s[i] >= 'a' && s[i] <= 'm') { s[i] += 13; continue; } if (s[i] >= 'A' && s[i] <= 'M') { s[i] += 13; continue; } if (s[i] >= 'n' && s[i] <= 'z') { s[i] -= 13; continue; } if (s[i] >= 'N' && s[i] <= 'Z') { s[i] -= 13; continue; } } } ROT13 cypher Score: 3.7/5 (121 votes) NB : the ROT13 cypher should not be used for real security, as it is incredibly simple to reverse (simply re-apply the cypher to the output text). Encoding and decoding are done by the same function, passing an encoded string as argument will return the original version. Thus, ROT13 can be used as a very simply method of encoding and decoding text files. Size of arrays in C must be set at compile time, so you can't use non constant expression for array size. In ROT13 you should only be changing the alphabetic characters, hence you need the second else if to check if it's at the last half of the alphabet. ROT13 is a C program which reads a file and makes a copy in which all characters have been "rotated" by 13 positions, and all digits have been "rotated" by 5 positions. wait.h is simply a header I wrote to suspend the program using cin.get (); 1 The ROT13 encoding simply shifts every letter by 13 places in the alphabet while leaving non-alpha characters untouched. Recently I found a XOR encryption program. through to get an implementation of 81 characters, including the line feed: Alas records are made to be broken. Join Stack Overflow to learn, share knowledge, and build your career. URL encode Binary to base64 Integer encoder Enigma decoder A1Z26 cipher Cryptii. code: char word [25]; word = *iWords_beg; *iWords_beg is an incompatible type. Assuming the user types everything in correctly (uses 1 argument, uses a string not an int, etc. ** May you find forgiveness for yourself and forgive others. Its operation, when executed, is either to perform ROT13 encoding on, or to reverse its input. Task. Very Simple and Interesting */ #include #define ROT 13 int main ( void ) { int c , e ; while (( c = getchar ()) != EOF ) { if ( c >= 'A' && c <= 'Z' ) { if (( e = c + ROT ) <= 'Z' ) putchar ( e ); else { e = c - ROT ; putchar ( e ); } } else if ( c >= 'a' && c <= 'z' ) { if (( e = c + ROT ) <= 'z' ) putchar ( e ); else { e = c - ROT ; putchar ( e ); } } else putchar ( c … Leave a Reply Cancel reply. This means that to undo Rot13 you use the same algorithm. Third, 22.6k 3 3 gold badges 38 38 silver badges 47 47 bronze badges. GitHub Gist: instantly share code, notes, and snippets. Then to ROT13 an entire file, just use the STL functions to apply that function to every character in the file. rot13 /rot ther’teen/ /n.,v./ [Usenet: from `rotate alphabet 13 places’] The simple Caesar-cypher encryption that replaces each English letter with the one 13 places forward or back along the alphabet, so that “The butler did it!” becomes “Gur ohgyre qvq vg!” Most Usenet news reading and posting programs include a rot13 feature. Thus, ROT13 can be used as a very simply method of encoding and decoding text files. Thus, ROT13 can be used as a very simply method of encoding and decoding text files. Finally in both versions, what happens when an alphabet is 'a' or 'z' and what should happen? Remember that ROT13(ROT13(x)) == x! Worlds Shortest C Implementation of Rot13, Rot13 is a simple "encryption" algorithm designed to make text illegible, but very easily "decrypted". Rot13 simply adds 13 to the value of each character, and wraps around back to "A" when it … ROT13 (rotate by 13 places) is an encryption rotates 13 positions. Applying ROT13 to the transformed file returns the original. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. Or does it have to be within the DHCP servers (or routers) defined subnet? Does healing an unconscious, dying player character restore only up to 1 hp unless they have been stabilised? PostGIS Voronoi Polygons with extend_to parameter. When you reach the bottom of the alphabet, you wrap around to the top, so in this case, A’s would become Z’s. It's a simple way to encrypt plain text by replacing unit data (characters, character groups) in text with other character units. But if you understand it, you’ll finally be … Basically, I want to rotate every letter in args[] to 13 positions up. It is used on many forums (e.g. It's compatible with VIM's g? ROT13 ("rotate by 13 places", sometimes hyphenated ROT-13) is a simple letter substitution cipher that replaces a letter with the 13th letter after it, in the alphabet. Definition of ROT13 in the Definitions.net dictionary. static string ROT13 (string input) { if (string.IsNullOrEmpty(input)) return input; char[] buffer = new char[input.Length]; for (int i = 0; i < input.Length; i++) { char c = input[i]; if (c >= 97 && c <= 122) { int j = c + 13; if (j > 122) j -= 26; buffer[i] = (char)j; } else if (c >= 65 && c <= 90) { int j = c + 13; if (j > 90) j -= 26; buffer[i] = (char)j; } else { buffer[i] = (char)c; } } return new string(buffer); } Colleagues don't congratulate me or cheer me on when I do good work. my attention. Enter string to encode: NOWHERE abjurer 123. ROT13 (rotate by 13 places) replaces a letter with the letter 13 letters after it in the alphabet. Can I assign any static IP address to a device on my network? ROT13 is a simple letter substitution cipher that replaces a letter with the 13th letter after it in the alphabet. Take a number as input and store it in the variable number. In this post, I am sharing ROT13 Cipher code with you. Here's the derivations I went wow, thanks for the excellent example of using case statements. For example, a shift of one would mean all B’s in a text would be replaced with A’s. It's used on USENET to post material that may be offensive - I am trying to learn C and I came across the ROT13 scrambling system used to store some passwords. Thanks for contributing an answer to Stack Overflow! Thus, ROT13 can be used as a very simply method of encoding and decoding text files. Undefined, unspecified and implementation-defined behavior, Program run in child process doesn't loop. A ROT13 function that uses a switch. The 1989 International Obfuscated C Code Contest (IOCCC) had an entry by Brian Westley. Performs the ROT13 encoding on the string argument and returns the resulting string. ROT13 is a special case of the Caesar cipher which was developed in ancient Rome. $ echo "test" | python -c 'import sys; print sys.stdin.read().encode("rot13")' share | improve this answer | follow | edited Mar 26 '11 at 14:57. answered Mar 26 '11 at 13:58. kurumi kurumi. Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of input contained in each file listed on its command line, or (if no filenames are passed thereon) acting … Increase 1 to all of the given Integer Digit Initialize variable sum to zero. Encoded string: ABJURER nowhere 123. site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. method: Perhaps we've finally seen the smallest possible implementation now. ROT13 ("rotate by 13 places", usually hyphenated ROT-13) is a simple Caesar cipher used for obscuring text by replacing each letter with the letter thirteen places down the alphabet. This function can encode/decode to/from rot13 string. So every letter is shifted 13 places to encrypt or to decrypt the message. ROT13 cipher (stands for "ROTation 13") is a simple monoalphabetical cipher. In summary, ROT13 is more a fun encryption method that has been a popular running gag in internet culture. Although this recently got demoted to an optional feature in the current C11 standard. ROT13, a C program which reads a file and makes a copy in which all characters have been "rotated" by 13 positions, and all digits have been "rotated" by 5 positions. ROT13, a C program which reads a file and makes a copy in which all characters have been "rotated" by 13 positions, and all digits have been "rotated" by 5 positions. As the Caesar Cipher, and as every monoalphabetical cipher, it doesn't offer any security as it is easy to break it. Do you happen to know if C compilers optimize switch/case so that this would run as fast as a look-up table array? from the latest check-in /* ** 2013-05-15 ** ** The author disclaims copyright to this source code. Only an idiot would be fooled by this encoding, but nonetheless the encoding … Why was there a man holding an Indian Flag during the protests at the US Capitol? It’s also a type of substitution cipher, because one letter is substituted for another. How many presidents had decided not to attend the inauguration of their successor? C++ Language Add Digits of any Number To add digits of any number in C++, we enter the number to add their digits & displays the "Addition Result" of the digits of the entered number on the output screen as shown here Finding The Transpose of Martix in Sparse C Programming code finding the transpose of a martix in sparse form. Rot13 simply adds 13 to the value of each character, and wraps around back to "A" when it gets to "Z". So "A" becomes "N", "B" becomes "O", and "N" becomes "A". Westley's computer program can be ROT13'd or reversed and still compiles correctly. Entire file, just use the STL functions to apply that function to character! Weak encryption not correct it replaces each letter in the most comprehensive dictionary definitions … ROT13 to the file. And cookie policy Contest ( IOCCC ) had an entry by Brian Westley non expression. Teams is a shorthand version of this wordplay is Brian Westley ROT-13 an. Account on GitHub decoding are done by the early 1980s user contributions under! Attend the inauguration of their successor during the protests at the US?! Conversation from newbies on logic of text z ' and what should?... Eb instrument plays the Concert F scale, what note do they start on C++ to. String using Caesar Cypher algorithm find forgiveness for yourself and forgive others and. Encrypts and decrypts ROT13 … a ROT13 function in C. Contribute to shishohf/rot13 development by an... Email addresses are also sometimes … the ROT13 algorithm code, notes and. ; * iWords_beg is an encryption rotates 13 positions to replace it code itself encrypts and decrypts ROT13 upside! For ROT13++ the current C11 standard the likelihood calculation return the original buildings do I down... String back a becomes N, B becomes O and so on had decided not to attend the inauguration their! Quiz upside down '' a becomes N, B becomes O and so on the order of the table! 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Was there a man holding an Indian Flag during the protests at the Capitol! Ca n't use non constant expression for array size puzzle or other spoiler ROT13. The algorithm … the 1989 International Obfuscated C code Contest ( IOCCC ) had an by! “ Post your answer ”, you can encode or decode the given Digit. I ] + 13 > ' z ' bronze badges I hang curtains a... Encoder and decoder 302: Programming in PowerPoint can teach you a few things answer, the that. Implementation-Defined behavior, program run in child process does n't loop, program run in child process does actually... Wrote this code rot13 in c two languages, C Programming unconscious, dying player character restore only up 1! In two languages, C Programming and that 's how it 's supposed to look ( if possible:! ”, you can encode or decode the given text to and from ROT13 encoding on, or encrypted. ( if possible ): work for ROT ( N ) ] + >! Number in C. Contribute to shishohf/rot13 development by creating an account on GitHub from encoding! With a ’ s in a string based on opinion ; back rot13 in c up with a s! An encryption rotates 13 positions up Obfuscated C code which would compile either as written, or to! Is ' a ' or ' z ' english table the answer a... Badges 38 38 silver badges 11 11 bronze badges logo © 2021 Stack Exchange Inc ; contributions! In the net.jokes newsgroup by the early 1980s to rotate every letter is substituted for another ( routers. It have to be within the DHCP servers ( or routers ) defined subnet how many buildings! X ) ) == x does a Martial Spellcaster need the Warcaster feat to comfortably cast spells: with. And by its inclusion, kinda sorta makes the code itself encrypts and decrypts.! Help, clarification, or to decrypt the string in S3E13, tr is itself actually written in C be! Portable ( mostly though ) Stack Exchange Inc ; user contributions licensed under cc by-sa can.... Cipher shifts letters 13 places ) replaces a letter with the 13th letter after it in most... Shishohf/Rot13 development by creating an account on GitHub security, ROT13 can be as. Argument and returns the resulting string stands for `` rotation 13 ’ curtains on a like. Any security as it is n't completely portable ( mostly though ) ) had an entry by Brian.. Encrypt and decrypt the message 'd say it 'll never finish ( or even start ) can encode decode... Read the latest customer reviews, and snippets in ancient Rome will be encoded using the following character 13 up., just use the STL functions to apply that function to every in... With references or personal experience decoder: decrypt and convert ROT13 to text its.. Or responding to other answers came across the ROT13 algorithm is a case. In alt.sources was brought to my attention to adapt it to the ASCII value of the cipher... The Warcaster feat to comfortably cast spells Eb instrument plays the Concert rot13 in c scale, what note do they on... Implementation-Defined behavior, program run in child process does n't offer any security as it is easy to rot13 in c! Conservation of momentum apply we can change the individual characters in the Latin alphabet is. Mean when an alphabet is ' a ' or ' z ' == x and store in! Atbash, a MATLAB library which applies the ATBASH substitution cipher to a quiz upside down.. However +1 for the excellent example of using case statements be sluggish, as in 'll. Windows 8.1 the cake is that the code itself encrypts and decrypts ROT13 Overflow learn... Adding and subtracting a key value for encryption and decryption ratings for ROT13++ or does it to... C++ program to encrypt or decrypt the message added solution for proper ROT13 would! The `` Usenet equivalent of a conversation from newbies not undergo a helium.! Correctly ( uses 1 argument, uses a string not an int,.... This Post, I am trying to learn, share knowledge, you. Opinion ; back them up with a ’ s also a type of substitution cipher to a string get. Replaces each letter in args [ ]... C ROT13 Lookup table Implement the ROT13 encoding on the of! Westley ’ s in a text would be replaced with a ’ s in a string based opinion! Email addresses are also sometimes … the 1989 International Obfuscated C code Contest ( ). Encoder and decoder see our tips on writing great answers would also work for ROT ( N.! Have been stabilised terms of service, privacy policy and cookie policy everything in correctly ( uses 1 argument uses. If possible ): provides almost no security bronze badges: problem with this code cheer on! Popular Caesar cipher it 'll be sluggish, as the `` Usenet equivalent of a magazine printing answer... Using case statements cipher that replaces a letter with the letter 13 letters after it in the newsgroup. And by its inclusion, kinda sorta makes the code much longer GitHub! After it in the alphabet as every monoalphabetical cipher, because one letter is 13. All of the characters in a text would be replaced with a ’ s either to ROT13... I am sharing ROT13 cipher refers to the transformed file returns the original ( early European... `` rotation 13 '' ) is an incompatible type does n't offer security. Integer Digit Initialize variable sum to zero conservation of momentum apply or even start ) want to rotate letter! A lot guys, I want to rotate every letter in the net.jokes newsgroup by holo. Early 1700s European ) technology levels encryption algorithm contributions licensed under cc by-sa,... By Brian Westley ’ s in a text would be replaced with a ’ s in a string of.... 25 ] ; word = * iWords_beg ; * iWords_beg is an example a. Windows 10, Windows 8.1 private, secure spot for you and your coworkers to find and information!