Can you use cat to send the first 25 lines of a file to the printer? I'm thinking I can pipe it with '|' but I'm not school to check printer output.
With the 'nl' used, all lines are numbered on the print out, but how does one number only the blank lines?
Thanks:) (1 Reply)
Hi,
I wnat to read a fiel line by line and store each line in a variabel, so I made a for loop:
for i in `cat file` ; do
#do sth.
done;
The problem is, that in the file, there are lines with only asterisks like this... (3 Replies)
Not sure how to do this exactly.. just want to take the first 100 lines of a file and cat it out into a second file. I know I can do a more on a file and > it into a different file, but how can I make it so only the first 100 lines get moved over? (1 Reply)
I want to cat a file with only show the line contain '/bin/bash' but don't show the line contain 'load' (don't show if the line contain 'load' and '/bin/bash' together), how to type in the command? thk a lot! (2 Replies)
I am looking for a command to take files with a specific date and cat them all into big file. I know I can use commands to list all of the files from a certain date. But I want to do that and take those files and make on large files containing all of them.
Any help would be great. This is being... (1 Reply)
Hi,
I have two files
one.txt
laptop
boy
apple
two.txt
unix
linux
OS
openS
I want to split one.txt into one line each and concatenate it with the two.txt
output files
onea.txt
laptop (4 Replies)
Hi All,
I have stumbled upon very unique issue. In my script I am doing cat file and then greping and cutting so as to assign the value to variable. My file is,
<mxc_tl_load_extractdata_prop.bsh>
DB_USER=test_oper
hostname=xxx
FTP_USER=test1_operate
MAIL_LIST=xxx@yyy.com... (1 Reply)
Hello,
I'm on a remote computer by SSH. How can I get the output of "cat file" into a file on the local computer?
I cannot use scp, because it's blocked.
something like:
ssh root@remote_maschine "cat /file" > /locale_machine/file
:rolleyes: (2 Replies)
Discussion started by: borsti007
2 Replies
LEARN ABOUT OSX
random
RANDOM(4) BSD Kernel Interfaces Manual RANDOM(4)NAME
random , urandom -- random data source devices.
SYNOPSIS
pseudo-device random
DESCRIPTION
The random device produces uniformly distributed random byte values of potentially high quality.
To obtain random bytes, open /dev/random for reading and read from it.
To add entropy to the random generation system, open /dev/random for writing and write data that you believe to be somehow random.
/dev/urandom is a compatibility nod to Linux. On Linux, /dev/urandom will produce lower quality output if the entropy pool drains, while
/dev/random will prefer to block and wait for additional entropy to be collected. With Yarrow, this choice and distinction is not necessary,
and the two devices behave identically. You may use either.
OPERATION
The random device implements the Yarrow pseudo random number generator algorithm and maintains its entropy pool. Additional entropy is fed
to the generator regularly by the SecurityServer daemon from random jitter measurements of the kernel. SecurityServer is also responsible
for periodically saving some entropy to disk and reloading it during startup to provide entropy in early system operation.
You may feed additional entropy to the generator by writing it to the random device, though this is not required in a normal operating envi-
ronment.
LIMITATIONS AND WARNINGS
Yarrow is a fairly resilient algorithm, and is believed to be resistant to non-root. The quality of its output is however dependent on regu-
lar addition of appropriate entropy. If the SecurityServer system daemon fails for any reason, output quality will suffer over time without
any explicit indication from the random device itself.
Paranoid programmers can counteract this risk somewhat by collecting entropy of their choice (e.g. from keystroke or mouse timings) and seed-
ing it into random directly before obtaining important random numbers.
FILES
/dev/random
/dev/urandom
HISTORY
A random device appeared in the Linux operating system.
Darwin September 6, 2001 Darwin