Sponsored Content
Full Discussion: Understanding sed
Top Forums Shell Programming and Scripting Understanding sed Post 302774017 by panyam on Friday 1st of March 2013 04:16:52 AM
Old 03-01-2013
Hi Scrutinizer,

Thanks for the reply. I got your second correctly.

Your first answer is slightly confusing me!..

Let's say the sample input is:

Code:
abcd:x:panyam:panyam:Panyam:512

echo "abcd:x:panyam:panyam:Panyam:512" | sed 's/^\([^:]*\):[^:]:/\1::/' gives me:

abcd::panyam:panyam:Panyam:512

\([^:]*\) matches : abcd
[^:] matches :x

\1 : prints only "abcd"..

Now, how the rest of the line is coming in output as it is? I mean
Code:
"panyam:panyam:Panyam:512"

.

Is it because sed prints the non matching patterns as it is?

Is my understanding correct?
 

9 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

need further understanding of init.d

I needt o know how what init.d does and how it knows which dameons/applications to turn off and how to restart the applications after reboot. any OS - solaris/hp-ux (1 Reply)
Discussion started by: jigarlakhani
1 Replies

2. Shell Programming and Scripting

understanding the sed command

Guys, I am trying to understand the sed command here. adx001 $ a=/clocal/dctrdata/user/dctrdat1/trdroot/recouncil adx001 $ b=`echo $a | sed 's/\//\\\\\//g'` adx001 $ echo $b \/clocal\/dctrdata\/user\/dctrdat1\/trdroot\/recouncil The sed command i took it from the script. Please... (3 Replies)
Discussion started by: mac4rfree
3 Replies

3. UNIX for Dummies Questions & Answers

Help understanding sed

I am trying to create a basic script that converts an Oracle script into a Sybase script. The only things im changing are Datatypes and the to_char and to_date functions. I am not really 100% sure of the way it works. I have tried running the functions through a loop to replace each word line... (6 Replies)
Discussion started by: Makaer
6 Replies

4. Shell Programming and Scripting

need help understanding mv

I just started shell coding and I'm a bit confused on how 'mv' works can someone explain to me how it works and if i did this correctly. Thanks. echo "Enter Name of the first file:" read file1 #echo $file1 if ; then echo "Sorry, file does not exist." exit 1 ... (16 Replies)
Discussion started by: taiL
16 Replies

5. UNIX for Dummies Questions & Answers

understanding {%/*}/

Hi Gurus: I am trying to understand the following line of code.I did enough of googling to understand but no luck.Please help me understand the follow chunk of code: X=$0 MOD=${X%/*}/env.ksh X is the current script from which I am trying to execute. Say if X=test.ksh $MOD is echoing :... (3 Replies)
Discussion started by: vemana
3 Replies

6. UNIX for Dummies Questions & Answers

understanding sed command

Hi Friends, I need a small help in understanding the below sed command. $ cat t4.txt 1 root 1 58 0 888K 368K sleep 4:06 0.00% init 1 root 1 58 0 888K 368K sleep 4:06 0.00% init last $ sed 's/*$//' t4.txt 1 root 1 58 0 888K ... (3 Replies)
Discussion started by: forroughuse
3 Replies

7. Shell Programming and Scripting

help understanding regex with grep & sed

I have the following line of code that works wonders. I just don't completely understand it as I am just starting to learn regex. Can you help me understand exactly what is happening here? find . -type f | grep -v '^\.$' | sed 's!\.\/!!' (4 Replies)
Discussion started by: trogdortheburni
4 Replies

8. Shell Programming and Scripting

Need your help in understanding this

Hi, I found this in a script and I would like to know how this works Code is here: # var1=PART1_PART2 # var2=${var1##*_} # echo $var2 PART2 I'm wondering how ##* makes the Shell to understand to pick up the last value from the given. (2 Replies)
Discussion started by: sathyaonnuix
2 Replies

9. Shell Programming and Scripting

Need Quick help on Understanding sed Regex

Hi Guys, Could you please kindly explain what exactly the below SED command will do ? I am quite confused and i assumed that, sed 's/*$/ /' 1. It will remove tab and extra spaces .. with single space. The issue is if it is removing tab then it should be Î right .. please assist.... (3 Replies)
Discussion started by: Nandy
3 Replies
WARPTENSORIMAGEMULTITRANSFORM(1)				   User Commands				  WARPTENSORIMAGEMULTITRANSFORM(1)

NAME
WarpTensorImageMultiTransform - part of ANTS registration suite DESCRIPTION
WarpImageMultiTransform ImageDimension moving_image output_image [-R reference_image | --tightest-bounding-box] (--reslice-by-header) [--use-NN (use Nearest Neighbor Interpolator)][--ANTS-prefix prefix-name | --ANTS-prefix-invert prefix-name] {[deformation_field | [-i] affine_transform_txt | --Id | [-i] --moving-image-header / -mh | [-i] --reference-image-header / -rh]} Example: Reslice the image: WarpIm- ageMultiTransform 3 Imov.nii Iout.nii --tightest-bounding-box --reslice-by-header Reslice the image to a reference image: WarpImageMulti- Transform 3 Imov.nii Iout.nii -R Iref.nii --tightest-bounding-box --reslice-by-header Note: -i will use the inversion of the following affine transform. --tightest-bounding-box will be overrided by -R reference_image if given. It computes the tightest bounding box using all the affine transformations. --Id uses the identity transform. --moving-image-header or -mh in short will use the orientation header of the moving image file. This is typically not used with --reslice-by-header. --reference-image-header or -rh in short will use the ori- entation header of the fixed image file. This is typically not used with --reslice-by-header. --reslice-by-header uses the orientation matrix and origin encoded in the image file header. It can be used together with -R. This is typically not used together with any other transforms. --reslice-by-header is equvalient to -i -mh, or -fh -i -mh if used together with -R. For ANTS users: To use with the deformation field and the affine transform files generated from ANTS: --ANTS-prefix prefix-name --ANTS-pre- fix-invert prefix-name Example: 3 moving_image output_image -R reference_image --ANTS-prefix abcd.nii.gz Applies abcdWarpxvec.nii.gz/abcd- Warpyvec.nii.gz/abcdWarpzvec.nii.gz and then abcdAffine.txt. Use this with ANTS to get the moving_image warped into the reference_image domain. 3 reference_image output_image -R moving_image --ANTS-prefix-invert abcd.nii.gz --ANTS-invert Applies the inversion of abcdAffine.txt and then abcdInverseWarpxvec.nii.gz/abcdInverseWarpyvec.nii.gz/abcdInverseWarpzvec.nii.gz. Use this with ANTS to get the reference_image warped into the moving_image domain. Note: prefix name "abcd" without any extension will use ".nii.gz" by default WarpTensorImageMultiTransform 1.9 May 2012 WARPTENSORIMAGEMULTITRANSFORM(1)
All times are GMT -4. The time now is 01:46 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy