Hi
I need a perl onliner which seaches a line starting with a pattern(last occurence) and display it.
similar to
grep 'pattern' filename | tail -1 in UNIX
Ex: I want to display the line starting with "cool" and which is a last occurence
adadfadafadf
adfadadf
cool dfadfadfadfara... (4 Replies)
I would like to use sed to replace one occurence of a pattern in a file. When I use the s/// command it replaces all occurences of the pattern in the file. Should I be using something other than sed?
Thanks (6 Replies)
hi,
is it possible to find the number of occurences of a pattern between two paranthesis.
for e.g
i have a file as below.
>>{
>>hi
>>GoodMorning
>>how are you?
>>}
>>is it good,
>>tell me yes, if it is good
In the above file, its clear the occurence of word "Good"... (17 Replies)
Hi
I have to replace a pattern found in the first uncommented line in a file. The challenge I'm facing is there are several such similar lines but I have to edit only the first uncommented line.
Eg:
#this is example
#/root/xyz:Old_Pattern
/root/xyz:Old_Pattern
/root/xyz:Old_Pattern
... (10 Replies)
Hi,
Do anybody know how to use awk to count the pattern at specific column?
Input file
M2A928K 419 ath-miR159a,gma-miR159a-3p,ptc-miR159a 60 miR235a
.
.
Output file
M2A928K 419 ath-miR159a,gma-miR159a-3p,ptc-miR159a 60 miR235a 3
.
.
I plan to count how many "miR" in column 3... (2 Replies)
Hi,
I have a simple problem but i guess stupid enough to figure it out. i have thousands rows of data. and i need to find match patterns of two columns and print the number of rows. for example:
inputfile
abd abp 123
abc abc 325
ndc ndc 451
mjk lkj... (3 Replies)
I have a large file and many lines are duplicated. I'm trying to delete lines with every second occurrence of a pattern. Did tried searching similar question but no luck.
I can delete all lines matching pattern with :g/pattern/d but don't want to lose data.
Sample pattern to delete... (6 Replies)
Hello.
Here is a file contents :
declare -Ax NEW_FORCE_IGNORE_ARRAY=(="§" ="§" ="§" ="§" ="§" .................. ="§"Here is a pattern
=I want to extract 'NEW_FORCE_IGNORE_ARRAY' which is the whole word before the first occurrence of pattern '='
Is there a better solution than mine :... (3 Replies)
Discussion started by: jcdole
3 Replies
LEARN ABOUT OPENDARWIN
stdbuf
STDBUF(1) User Commands STDBUF(1)NAME
stdbuf - Run COMMAND, with modified buffering operations for its standard streams.
SYNOPSIS
stdbuf OPTION... COMMAND
DESCRIPTION
Run COMMAND, with modified buffering operations for its standard streams.
Mandatory arguments to long options are mandatory for short options too.
-i, --input=MODE
adjust standard input stream buffering
-o, --output=MODE
adjust standard output stream buffering
-e, --error=MODE
adjust standard error stream buffering
--help display this help and exit
--version
output version information and exit
If MODE is 'L' the corresponding stream will be line buffered. This option is invalid with standard input.
If MODE is '0' the corresponding stream will be unbuffered.
Otherwise MODE is a number which may be followed by one of the following: KB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T,
P, E, Z, Y. In this case the corresponding stream will be fully buffered with the buffer size set to MODE bytes.
NOTE: If COMMAND adjusts the buffering of its standard streams ('tee' does for example) then that will override corresponding changes by
'stdbuf'. Also some filters (like 'dd' and 'cat' etc.) don't use streams for I/O, and are thus unaffected by 'stdbuf' settings.
EXAMPLES
tail -f access.log | stdbuf -oL cut -d ' ' -f1 | uniq
This will immediately display unique entries from access.log
BUGS
On GLIBC platforms, specifying a buffer size, i.e., using fully buffered mode will result in undefined operation.
AUTHOR
Written by Padraig Brady.
REPORTING BUGS
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Report stdbuf 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
Full documentation at: <http://www.gnu.org/software/coreutils/stdbuf>
or available locally via: info '(coreutils) stdbuf invocation'
GNU coreutils 8.28 January 2018 STDBUF(1)