topic Re: Corrupted files in Operating System - HP-UX

Corrupted files

Leif Halvarsson_2 — Tue, 29 Apr 2003 10:10:02 GMT

Hi
I have found some corrupted files on one filesystem. The files is ordinary text files. Is there any fast way to check if a file contains only printable characters.

Re: Corrupted files

Cheryl Griffin — Tue, 29 Apr 2003 10:12:50 GMT

How about:
# cat filename |vis

vis will show garbage as \002 for example.

Re: Corrupted files

Robert-Jan Goossens — Tue, 29 Apr 2003 10:13:21 GMT

Hi,

# file *

Robert-Jan.

Re: Corrupted files

T G Manikandan — Tue, 29 Apr 2003 10:23:41 GMT

#file

Re: Corrupted files

Balaji N — Tue, 29 Apr 2003 10:27:15 GMT

hi,

man file.

to view the contents, strings filename.

-balaji

Re: Corrupted files

Michael Steele_2 — Tue, 29 Apr 2003 11:20:44 GMT

file file_name

...will report ascii text or not. ASCII text is printable characters.

strings file_name |more

...will allow you to convert binary to ascii text for reading purposes.

Re: Corrupted files

Ian Lochray — Tue, 29 Apr 2003 11:54:37 GMT

Be carefull if you decide to use file from a script and check the output from the command for "ascii text" as the file command will attempt to try to find out what language an ascii file is written in (see man file). This guess can often be wrong. FOr instance, file believes that my /etc/hosts file is "s200 assembler program text".

Re: Corrupted files

Bill Hassell — Tue, 29 Apr 2003 13:45:57 GMT

As mentioned, the file command can be used to 'guess' what the contents might be. The problem is that unlike commercial operating systems, Unix does not maintain a concept of a file type. All ordinary files are simply a stream of bytes and only the creator knows what the file's content and purpose might be.

As mentioned, the vis command can be used scan a file and if the output contains \0something, then there is at least one non-printable ASCII character.

Re: Corrupted files

Leif Halvarsson_2 — Tue, 29 Apr 2003 14:29:21 GMT

Hi,

Thank you everybody. vis show there is strange characters in som of the files. The problem seems to be with large files (>1MB). I think I first have to find out how the files have been corrupted.

Re: Corrupted files

Michael Steele_2 — Tue, 29 Apr 2003 14:47:17 GMT

'cksum' is a quick test of corruption when transporting files, say from one server to another via ftp, or when copying files between new and old file systems.

'cksum' executes a hashing algorithm for the puspose of error correction and the results will be the same if a successful transport occurred.