Flashnux

GNU/Linux man pages

Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :

ISBN : 978-2-7460-9712-4
EAN : 9782746097124
(Editions ENI)

Unix

Unix v6

diff(1)



diff differential file comparator [ ] name1 name2 tells what lines must be changed in two files to bring them into agreement. The normal output contains lines of these forms: a
d
c These lines resemble commands to convert file into file The numbers after the letters pertain to file In fact, by exchanging ‘a’ for ‘d’ and reading backward one may ascertain equally how to convert file into As in identical pairs where = or = are abbreviated as a single number. Following each of these lines come all the lines that are affected in the first file flagged by ‘*’, then all the lines that are affected in the second file flagged by ‘.’. Under the option, the output of is a script of and commands for the editor which will change the contents of the first file into the contents of the second. In this connection, the following shell program may help maintain multiple versions of a file. Only an ancestral file ($1) and a chain of version-to-version scripts ($2,$3,...) made by need be on hand. A ‘latest version’ appears on the standard output. (cat $2 ... $9; echo "1,$p") ed $1 Except for occasional ‘jackpots’, finds a smallest sufficient set of file differences. cmp (I), comm (I), ed (I) ‘jackpot’ To speed things up, the program uses hashing. You have stumbled on a case where there is a chance that this has resulted in a difference being called where none actually existed. Sometimes reversing the order of files will make a jackpot go away. Editing scripts produced under the
option are naive about creating lines consisting of a single ‘.’.



diff(1)