This requires ksh and a lot of memory, but if it runs, it will be rather fast.
Code:
#! /usr/bin/ksh
exec < weblog
IFS=""
while read line ; do
ip=${line%% *}
octet4=${ip##*.}
ip=${ip%.$octet4}
octet3=${ip##*.}
ip=${ip%.$octet3}
octet2=${ip##*.}
octet1=${ip%.$octet2}
ip=${octet1}_${octet2}_${octet3}_${octet4}
var=array_$ip
eval $var=\$line
done
IFS="\="
set | while read variable value ; do
if [[ $variable = array_+([0-9])_+([0-9])_+([0-9])_+([0-9]) ]] ; then
echo "$value"
fi
done
exit 0
For some reason 8.1 Mandrake Linux seems much slower than Windows 2000 with my cable modem. DSL reports test says they conferable speed with Windows2 though.
This is consistant slow with both of my boxes, at the same time. Linux used to be faster, but not with Mandrake. Any way to fix this? (17 Replies)
Hi ,
I need to copy every day about 35GB of files from one file system to another.
Im using the cp command and its toke me about 25 min.
I also tried to use dd command but its toke much more.
Is there better option ?
Regards. (6 Replies)
Hi I have to grep for 2000 strings in a file one after the other.Say the file name is Snxx.out which has these strings.
I have to search for all the strings in the file Snxx.out one after the other.
What is the fastest way to do it ??
Note:The current grep process is taking lot of time per... (7 Replies)
I have read anecdotes about people installing RAID0 (RAID - Wikipedia, the free encyclopedia) on some of their machines because it gives a performance boost. Because bandwidth on the motherboard is limited, can someone explain exactly why it should be faster? (7 Replies)
Hi all,
In bash scripting, I use to read files:
cat $file | while read line; do
...
doneHowever, it's a very slow way to read file line by line.
E.g. In a file that has 3 columns, and less than 400 rows, like this:
I run next script:
cat $line | while read line; do ## Reads each... (10 Replies)
I have the following code running against a file. The file can have upwards of 10000 lines.
problem is, the for loop takes a while to go through all those lines. is there a faster way to go about it?
for line in `grep -P "${MONTH} ${DAY}," file | ${AWK} -F" " '{print $4}' | awk -F":"... (2 Replies)
i'm trying to decide if to move operations from one of these hosts to the other. but i cant decide which one of them is the most powerful.
each host has 8 cpus.
HOSTA
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 44
model name : Intel(R) Xeon(R) CPU ... (6 Replies)
Hello,
I am under Ubuntu 18.04 Bionic.
I have one shell script run.sh (which is out of my topic) to run files under multiple directories and one file to control all processes running under those directories (control.sh).
I set a cronjob task to check each of them with two minutes of intervals.... (3 Replies)
Discussion started by: baris35
3 Replies
LEARN ABOUT X11R4
exec
exec(1) User Commands exec(1)NAME
exec, eval, source - shell built-in functions to execute other commands
SYNOPSIS
sh
exec [argument...]
eval [argument...]
csh
exec command
eval argument...
source [-h] name
ksh
*exec [arg...]
*eval [arg...]
DESCRIPTION
sh
The exec command specified by the arguments is executed in place of this shell without creating a new process. Input/output arguments may
appear and, if no other arguments are given, cause the shell input/output to be modified.
The arguments to the eval built-in are read as input to the shell and the resulting command(s) executed.
csh
exec executes command in place of the current shell, which terminates.
eval reads its arguments as input to the shell and executes the resulting command(s). This is usually used to execute commands generated as
the result of command or variable substitution.
source reads commands from name. source commands may be nested, but if they are nested too deeply the shell may run out of file descrip-
tors. An error in a sourced file at any level terminates all nested source commands.
-h Place commands from the file name on the history list without executing them.
ksh
With the exec built-in, if arg is given, the command specified by the arguments is executed in place of this shell without creating a new
process. Input/output arguments may appear and affect the current process. If no arguments are given the effect of this command is to mod-
ify file descriptors as prescribed by the input/output redirection list. In this case, any file descriptor numbers greater than 2 that are
opened with this mechanism are closed when invoking another program.
The arguments to eval are read as input to the shell and the resulting command(s) executed.
On this man page, ksh(1) commands that are preceded by one or two * (asterisks) are treated specially in the following ways:
1. Variable assignment lists preceding the command remain in effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. Words, following a command preceded by ** that are in the format of a variable assignment, are expanded with the same rules as a vari-
able assignment. This means that tilde substitution is performed after the = sign and word splitting and file name generation are not
performed.
EXIT STATUS
For ksh:
If command is not found, the exit status is 127. If command is found, but is not an executable utility, the exit status is 126. If a redi-
rection error occurs, the shell exits with a value in the range 1-125. Otherwise, exec returns a zero exit status.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO csh(1), ksh(1), sh(1), attributes(5)SunOS 5.10 17 Jul 2002 exec(1)