Looks like there are a couple of bugs there. The first, a typo of Z for B, always exits before selecting anything. The second, the for-loop post-increment expression, can cause the algorithm to yield anywhere between 1 and 200 lines.
Probably no need to fix it since Scrutinizer's first example in post #5 is a correct implementation of the same approach.
Regards,
Alister
---------- Post updated at 06:28 PM ---------- Previous update was at 06:26 PM ----------
With regard to all of the AWK suggestions, without knowing exactly how the script is to be used, it's possible that all of the recommendations are inadequate. Nearly every awk srand implementation's default seed is the number of seconds since the epoch. Successive or simultaneous runs could yield identical results. May or may not be an issue. We don't have sufficient information to make that determination. Just a head's up for the OP.
If it is an issue, more information would be required to determine a robust seed expression.
on my desktop i am using the kde rotating desktop image option. this rotates images randomly every half hour. now, i would like to write an html file which will have an inline frame with some text, maybe system messages, or my friends live journal thati read alot, or unix.com! however, i dont want... (1 Reply)
Hi,
From some time, we have noticed that our ascii files have started corrupting due to the presence of some random control characters (^@, ^M, ^H, ^D). The characters appear randomly on any file after the process that creates the file finishes. If we rerun the process, the files re creates... (0 Replies)
I want to take the below data, and have it output to file only the STMC#/(IP address) and the "there are X number of updates to install" lines for each machine. I know it's easy, but Im a beginner in BASH stuff, my solution would probably take way too many lines to do something easy.Thanks!
... (5 Replies)
Hi there, I have a text file with several colums separated by "|;#" I need to search the file extracting all columns starting with the value of "1" or "2" saving in a separate file just the first 7 columns of each row maching the criteria, with replacement of the saparators in the nearly created... (4 Replies)
i have a file in following format
1 32 3
4 6 4
4 45 1
45 4 61
54 66 4
5 65 51
56 65 1
12 32 85
now here the total number of lines are 8(they vary each time)
Now i want to select only those lines in which the values... (6 Replies)
What I have are two text files that I need to shuffle randomly, but I need the two files to be randomly shuffled the same way. I have heard of shuf but I do not know how to use it for two files. Maybe there is also an easy/simple awk command I do not know about that could handle this problem.
... (3 Replies)
Hello,
This is my code:
nb_lignes=`wc -l $1 | cut -d " " -f1`
for i in $(seq $nb_lignes)
do
m=`head $1 -n $i | tail -1`
//command
done
Please how can i change it to get Get 20% of lines in File randomly to apply "command" on each line ? 20% or 40% or 60 % (it's a parameter)
Thank you. (15 Replies)
Hi
I need to select lines from a txt file, I have got a line starting with ZMIO:MSISDN= and after a few line I have another line starting with 'MOBILE STATION ISDN NUMBER' and another one starting with 'VLR-ADDRESS' I need to copy these three lines as three different columns in a separate... (3 Replies)
Dear Folks
I have one column of 15000 lines and want to select randomly 5000 of them in five different times without replacement. I am aware that command 'shuf' and 'sort -R' could select randomly those lines but I am not sure how could I avoid the replacement of selection line. Does anyone have... (10 Replies)
hi all,
trying this using shell/bash with sed/awk/grep
I have two files, one containing one column, the other containing multiple columns (comma delimited).
file1.txt
abc12345
def12345
ghi54321
...
file2.txt
abc1,text1,texta
abc,text2,textb
def123,text3,textc
gh,text4,textd... (6 Replies)
Discussion started by: shogun1970
6 Replies
LEARN ABOUT X11R4
head
HEAD(1) User Commands HEAD(1)NAME
head - output the first part of files
SYNOPSIS
head [OPTION]... [FILE]...
DESCRIPTION
Print the first 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options too.
-c, --bytes=[-]NUM
print the first NUM bytes of each file; with the leading '-', print all but the last NUM bytes of each file
-n, --lines=[-]NUM
print the first NUM lines instead of the first 10; with the leading '-', print all but the last NUM lines of each file
-q, --quiet, --silent
never print headers giving file names
-v, --verbose
always print headers giving file names
-z, --zero-terminated
line delimiter is NUL, not newline
--help display this help and exit
--version
output version information and exit
NUM may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T,
P, E, Z, Y.
AUTHOR
Written by David MacKenzie and Jim Meyering.
REPORTING BUGS
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Report head translation bugs to <http://translationproject.org/team/>
COPYRIGHT
Copyright (C) 2017 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
SEE ALSO tail(1)
Full documentation at: <http://www.gnu.org/software/coreutils/head>
or available locally via: info '(coreutils) head invocation'
GNU coreutils 8.28 January 2018 HEAD(1)