read in file

[Bhoyet Orillo]

Is there a way to read a specified number of bytes in
a file using a script?

[Steven Sim Kok Leong]

Hi,

Please refer to:

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xbe4ac4c76f92d611abdb0090277a778c,00.html

Hope this helps. Regards.

Steven Sim Kok Leong

[Mark Greene_1]

see the man page for dd. There are flags to specify the source file and the block size in 512-byte increments.

HTH
mark

[Peter Kloetgen]

Hi Bhoyet,

you can use the dd- command:

dd if=/path/to/file bs=1 count=30

brings 30 bytes to standard output.

var=`dd if=/path/to/file bs=1 count=30`

gives the first 30 bytes of your file as value to the variable "var"

Allways stay on the bright side of life!

Peter

[Rodney Hills]

Use could us "head" command with "-c" option.

head -c -n 1000 filex >first1000bytes

Would copy only the first 1000 bytes from filex.

-- Rod Hills

[A. Clay Stephenson]

Really Perl is the scripting language of choice for this.


open F1, "$n = read(F1,$s_in,8192);
# $n - number of bytes read
# $s_in contains the data up to 8192 bytes

# now seek to offset 32768 and read again
seek(F1,32768,0);
$n = read(f1,$s_in,8192);
close F1;

You would, of course, need to add some error checking but this is the clean scripting way to do this.