03-12-2013
Well, you can *seek() to an offset, or you can search to a pattern, which is *read(). Many systems have ksh93 as dtksh in the CDE bin!
Yes, that loops forever. If you want it to break, make it 'while [ ! -f fileN ]', where fileN is the file created by sed w for the end pattern.
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Working in HP-UX 10.20. I eventually want to write a bourne shell script to handle the following problem, but for now I am just toying with it at the command line.
Here's what I am basically trying to do:
tail -f log_X | grep n > log_Y
I am doing a tail -f on log_X . Once it sees "n", I... (6 Replies)
Discussion started by: cdunavent
6 Replies
2. Shell Programming and Scripting
Hello all,
I have search the forum and could not find an answer...Here is what I am trying to do. Every 15 minutes, a script send uptime output to a logfile (dailylog.log), that file contains lines like the one below:
11:21am up 44 days, 19:15, 1 user, load average: 0.00, 0.02, 0.03
... (7 Replies)
Discussion started by: qfwfq
7 Replies
3. Shell Programming and Scripting
I am trying to extract a particular line from a.log which keeps appending every sec and output that into a newfile b.log which should append itself with filtered data received from a.log
I tried
tail -f a.log |grep fail| tee -a b.log
nothing in b.log
tail -f a.log |grep fail >>b.log
... (4 Replies)
Discussion started by: wannalearn
4 Replies
4. HP-UX
Hello again,
We need to install patches to HP-UX B.11.11 but would like to break the mirror it has (with out damaging it) so that in case of failure we can use this a meassure procedure.
Any ideas on how to do this
Thank you! (2 Replies)
Discussion started by: AQG
2 Replies
5. Shell Programming and Scripting
is it possible? because i still need to keep on reading even though i don't want to read that particular line (7 Replies)
Discussion started by: finalight
7 Replies
6. Shell Programming and Scripting
Hi,
i have a file say samp.s which has
123 a b c d
123 e f g h
123 i j k l
123 m n o p
234 a b c d
234 e f g h
234 i j k l
the first 3 characters in each line are considered the key values
i have one more file temp.txt which has
123
234
i want to have a page break in... (5 Replies)
Discussion started by: Sheema
5 Replies
7. Shell Programming and Scripting
hi guys
I am working on a menu for linux... some basic stuff.
but I have an issue. I got 1 server where something is working and the same thing does not work in the same way in another linux box
Basically I am simulating a command line where user insert some commands and to end and go back... (7 Replies)
Discussion started by: karlochacon
7 Replies
8. Shell Programming and Scripting
...when the lines use both a colon and commas to separate the parts you want read as information.
The first version of this script used cut and other non-Bash-builtins, frequently, which made it nice and zippy with little more than average processor load in GNOME Terminal but, predictably, slow... (2 Replies)
Discussion started by: SilversleevesX
2 Replies
9. Shell Programming and Scripting
I have 250 files that have 16 columns each - all numbered as follows stat.1000, stat.1001, stat.1002, stat.1003....stat.1250.
I would like to join all 250 of them together tail by tail as follows. For example
stat.1000
a b c
d e f
stat.1001
g h i
j k l
So that my output... (2 Replies)
Discussion started by: kayak
2 Replies
10. Shell Programming and Scripting
because the tail +2 on the first line gives me the file name pomga I do not want anything like what I miss
tail +2 ejemplo.txt
ouput
==> ejemplo.txt <==
1
2
3
4
5
6
7
8
9
10 (2 Replies)
Discussion started by: tricampeon81
2 Replies
seek(n) Tcl Built-In Commands seek(n)
__________________________________________________________________________________________________________________________________________________
NAME
seek - Change the access position for an open channel
SYNOPSIS
seek channelId offset ?origin?
_________________________________________________________________
DESCRIPTION
Changes the current access position for channelId.
ChannelId must be an identifier for an open channel such as a Tcl standard channel (stdin, stdout, or stderr), the return value from an
invocation of open or socket, or the result of a channel creation command provided by a Tcl extension.
The offset and origin arguments specify the position at which the next read or write will occur for channelId. Offset must be an integer
(which may be negative) and origin must be one of the following:
start The new access position will be offset bytes from the start of the underlying file or device.
current The new access position will be offset bytes from the current access position; a negative offset moves the access position back-
wards in the underlying file or device.
end The new access position will be offset bytes from the end of the file or device. A negative offset places the access position
before the end of file, and a positive offset places the access position after the end of file.
The origin argument defaults to start.
The command flushes all buffered output for the channel before the command returns, even if the channel is in nonblocking mode. It also
discards any buffered and unread input. This command returns an empty string. An error occurs if this command is applied to channels
whose underlying file or device does not support seeking.
Note that offset values are byte offsets, not character offsets. Both seek and tell operate in terms of bytes, not characters, unlike
read.
EXAMPLES
Read a file twice:
set f [open file.txt]
set data1 [read $f]
seek $f 0
set data2 [read $f]
close $f
# $data1 == $data2 if the file wasn't updated
Read the last 10 bytes from a file:
set f [open file.data]
# This is guaranteed to work with binary data but
# may fail with other encodings...
fconfigure $f -translation binary
seek $f -10 end
set data [read $f 10]
close $f
SEE ALSO
file(n), open(n), close(n), gets(n), tell(n), Tcl_StandardChannels(3)
KEYWORDS
access position, file, seek
Tcl 8.1 seek(n)