Hello All,
I just wanted to know what are the different ways of using commands in combination.
The most common one which i know is using pipes.
Also grouping is also done like ( ls; date) where output of both the commands is displayed.
Are there any other ways of combining various... (2 Replies)
I want to show a output like this
Lee Ballancore
PID TTY TIME CMD
31799 pts/3 00:00:00 vim
31866 pts/3 00:00:00 vim
2495 pts/7 00:00:00 vim
8368 pts/0 00:00:00 vim
9544 pts/2 00:00:00 ps
Alistairr Rutherford
PID TTY TIME CMD
8368 pts/0 00:00:00 vim
9544 pts/2 00:00:00 ps
... (3 Replies)
Hi,
I am cutting data from a fixed length test file and then writing out a new record using the echo command, the problem I have is how to stop multiple spaces from being written to the output file as a single space.
Example:
cat filea | while read line
do
field1=`echo $line | cut -c1-2`
... (6 Replies)
I have a file split something like
01/11/2010:
No of users 100
02/11/2010:
No of users 102
03/11/2010:
No of users 99
...
I want to search the file for a particular date and then extract the following line with the date, something like
02/11/2010 No of users 102
I can grep... (6 Replies)
I have an awk script to find the maximum value of the 2nd column of a 2 column datafile, but I need to find the top 5 maximum values of the 2nd column.
Here is the script that works for the maximum value.
awk 'BEGIN { subjectmax=$1 ; max=0} $2 >= max {subjectmax=$1 ; max=$2} END {print... (3 Replies)
Hi,
I am getting crazy after days on looking at it:
Bash in Ubuntu 12.04.1
I want to do this:
pattern="system /path1/file1 file1"
new_pattern=" data /path2/file2 file2"
file to edit: data.db
- I need to search in the file data.db for the nth occurrence of pattern
- pattern must... (14 Replies)
I have a file1 like
prt1|als28.1 prt3|als53.1 prt2|als550.1 prt1|bls9.2 prt2|als7.2 prt2|bls0.2
prt2|als872.1 prt1|bls871.1 prt2|als6.2 prt4|als22.1 prt2|bls43.2
I want to create a file2 from this file by comparing all the possible combinations of patterns (prt) assuming prt1... (3 Replies)
Im currently running this command to satisfy a particular task. it works for my purposes. but i want to be able to optimize this string of commands and have it be reduced to 1 or 2 commands, if at all possible:
head -4 datafile 2>/dev/null | cut -c1-400 | wc | awk '{print $2$1$3}' (5 Replies)
In the awk below I am trying to remove all lines above and including the pattern Test or Test2. Each block is seperated by a newline and Test2 also appears in the lines to keep but it will always have additional text after it. The Test to remove will not. The awk executed until the || was added... (2 Replies)
Discussion started by: cmccabe
2 Replies
LEARN ABOUT PLAN9
grep
GREP(1) General Commands Manual GREP(1)NAME
grep - search a file for a pattern
SYNOPSIS
grep [ option ... ] pattern [ file ... ]
DESCRIPTION
Grep searches the input files (standard input default) for lines (with newlines excluded) that match the pattern, a regular expression as
defined in regexp(6). Normally, each line matching the pattern is `selected', and each selected line is copied to the standard output.
The options are
-c Print only a count of matching lines.
-h Do not print file name tags (headers) with output lines.
-i Ignore alphabetic case distinctions. The implementation folds into lower case all letters in the pattern and input before interpre-
tation. Matched lines are printed in their original form.
-l (ell) Print the names of files with selected lines; don't print the lines.
-L Print the names of files with no selected lines; the converse of -l.
-n Mark each printed line with its line number counted in its file.
-s Produce no output, but return status.
-v Reverse: print lines that do not match the pattern.
Output lines are tagged by file name when there is more than one input file. (To force this tagging, include /dev/null as a file name
argument.)
Care should be taken when using the shell metacharacters $*[^|()= and newline in pattern; it is safest to enclose the entire expression in
single quotes '...'.
SOURCE
/sys/src/cmd/grep.c
SEE ALSO ed(1), awk(1), sed(1), sam(1), regexp(6)DIAGNOSTICS
Exit status is null if any lines are selected, or non-null when no lines are selected or an error occurs.
GREP(1)