Is there a standard way to make a shell script read a file, or list, and skip each line that contains # at the begining, or ignores the content starting after a # in line?
I'm looking to mimic the way commenting in a shell script normally works. This way I can comment my text files and lists my... (4 Replies)
From the below file I want to grep only the lines except the comment sections. But grep -v "#" is eliminating the last line because it has one # in between.
Any idea how can I ignore only the lines which have # at the begining (I mean comment lines) ?
Thanks a lot to all in advance
C Saha (1 Reply)
Hello,
I'm trying to move the last word of matching pattern to the begining of next line. Appreciate if anyone post the script.
From the below line I'm getting the last word, Note: this word also appears in many places in my file
#return the last word of line that contains ListenPort
sed... (4 Replies)
Hello!
Im trying to read file contents. Then, print out every line that has "/bens/here" in the file that was read.
cat /my/file.now | sed '/bens/here/p'
I keep getting the error asking if I need to predeclare sed?
What does predeclaring sed mean?
Thanks!
Ben (2 Replies)
Hi guys.
I need a sed command to print like 10 lines after a regular expression is found in the log.
Can anyone help me out.
Thanks
---------- Post updated at 10:52 AM ---------- Previous update was at 10:34 AM ----------
never mind.
I just did the search bewteen two expressions. (1 Reply)
I am trying to extract a table of data (mysql query output) from a log file. I need to print everything below the header and not past the end of the table. I have spent many hours searching with little progress. I am matching the regexp +-\{99\} with no problem. I just can't figure out how to print... (5 Replies)
Hi All
I'm trying to extract the line just above a regexp and all lines after this.
I'm currently doing this in two steps
sed -n -e "/^+---/{g;p;}" -e h oldfile.txt > modified.txt
sed -e "1,/^+---/d" -e "/^$/d" oldfile.txt >>modified.txt
Sample
sometext will be here
sometext will be... (3 Replies)
I am getting the varible value from a grep command as:
var=$(grep "Group" File1.txt | sed 's/Group Name*//g;s/,//g;s/://g;s/-//g')
which leaves me the value of $var=xyz.
now i want to append $var value in the begining of all the lines present in the file. Can u please suggest?
Input file:
1... (10 Replies)
Use sed to print first n lines and last n lines of an output.
For example: n=10
Can it be done?
Thanks. (7 Replies)
Discussion started by: carloszhang
7 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)