| What is file sharing? In computing there is a software | | | | the research for this. This was in terms of intellectual |
| which performs the function of file comparing. It | | | | capital, manpower and systems. It was called Project |
| outputs the differences between two files. The | | | | Xanadu and this is the conceptual predecessor of diff. |
| program displays the changes made per line for text | | | | It was conceived in 1960 as hypertext project first. It |
| files. The 'diff' is a file comparison utility that performs | | | | was supposed to include a version tracking system |
| this function. Modern implementations also support | | | | necessary for its 'transpointing windows' feature. The |
| binary files. The output is called a diff or more | | | | feature subsumed file differences in the expansive |
| commonly a patch since the output can be applied | | | | term 'transclusion', where a document has included in it |
| with the program patch. Just like the word 'grep' is | | | | parts of other documents or revisions. 'Diff' and its |
| used for the act of searching, the word diff is used in | | | | cousins. Diff is based on an algorithm. It is based on |
| jargon as a verb for calculating any difference. The | | | | solving the Longest Common Subsequence [LCS] |
| 'diff' utility was developed in the early 1970's on the | | | | problem. It works on the principle of invoking the |
| UNIX operating system in the AT&T labs in the USA. | | | | command line with the names of two files: diff original |
| Understanding 'diff'. In the context of the UNIX | | | | new. The changes form the output of the command |
| operating system the use of the 'ed' line editor | | | | required to turn the original file into the new file. If the |
| provided diff with the natural ability to create machine | | | | original and new are directories, the diff will run on each |
| usable 'edit scripts.' These edit scripts when saved to a | | | | of the files. The diff will cover both files. An option |
| file, can with the original file be reconstituted by 'ed' into | | | | called -r will compare files between directories. There |
| the modified file in its entirety. This greatly reduces the | | | | are several variations of diff. The core algorithm |
| secondary storage required to maintain multiple | | | | remains the same but there are modifications to the |
| versions of a file. When diff was launched initially the | | | | core algorithm. This has resulted in addition of useful |
| most common uses were comparing changes in the | | | | features to the command, and the design of new |
| source of software code and mark up for technical | | | | output formats. Other variations such as sdiff and |
| documents, verifying program debugging output, | | | | diffmk render side by side diff listings. File sharing |
| comparing file system listings and analyzing computer | | | | software is steadily increasing in its usage over the |
| assembly code. The output set for 'ed' was with the | | | | years. The software industry sees a big revenue |
| objective of providing compression for a sequence of | | | | generation opportunity in file sharing programs and is |
| modifications. Storing edit scripts with diff led to the | | | | investing a lot more in this product category. |
| invention of the Source Code Control System. Before | | | | If you are interested in free file compare, check this |
| diff was created a lot of resources were poured into | | | | web-site to learn more about document comparison. |