$ diff /usr/share /usr/local/share
$ diff /usr/bin/test /usr/bin/[ или $ diff /bin/test /bin/[ $ ls -i /usr/bin/test /usr/bin/[ или $ ls -i /bin/test /bin/[
$ cat hello.c
#include <stdio.h> main () { printf("Hello World\n"); }
$ cp hello.c hello.c.old $ cat hello.c
#include <stdio.h> main () { printf("Hello World Again\n"); }
$ diff hello.c.old hello.c
3c3 < printf("Hello World\n"); --- > printf("Hello World Again\n");
diff -e hello.c.old hello.c
3c printf("Hello World Again\n"); .
$ diff hello.c.old hello.c > hello.patch $ mv hello.c.old hello.c $ patch hello.c hello.patch $ cat hello.c
#include <stdio.h> main () { printf("Hello World Again\n"); }