search and replace in a binary file

[mors123456]

hi !

i need a help to change a binary file, let's say to find and replace username:

find string: "/home/name/bla-bla-bla/ "
new string: "/home/anewname/bla-bla-bla/ "

i can do it, for example, in emacs (hexl-mode), but interesting in writing a script instead. it will be much more better for me if i could do it automatically.

is there an analog of: sed 's/string1/string2/g' ?

P.S. the best way is to recompile the binary files i have, but there are no sources available.

[clowenstein]

It depends greatly on whether the binary file has other properties that must not be changed when you replace the string. Such as a fixed length, or a required checksum.

[mors123456]

thank you for your reply. i solved the problem. the simple SED works perfectly in my case, i only need to check that the length remains fixed. that was the actual problem... my stupid

now i can do all i want in a very simple way!

[jippie]

If you have root access, create a symlink if all you want to do is change the path to a home directory:

ln -s /home/name /home/anewname

[unlimitedscolobb]

the simple SED works perfectly in my case, i only need to check that the length remains fixed.

In most cases you can also substitute with shorter zero-padded strings, unless the program expects a different string terminator character.

[mors123456]

thank you for the answers.

to jippie: that is clearly an option, i'll keep it mind

to unlimitedscolobb: yes, agree. that is how i finally did it.