Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: What should be precedence of using awk, sed, head and tail in UNIX?
Top Forums UNIX for Dummies Questions & Answers What should be precedence of using awk, sed, head and tail in UNIX? Post 302800955 by hanson44 on Wednesday 1st of May 2013 01:14:07 AM
Old 05-01-2013
There is no hard and fast rule. But from my experience:

Learn head and tail first, and use them preferably. They are simple and well suited to specific task. uniq, grep and tr are also quite useful and powerful.

Use sed and awk next. These are more difficult to understand, and both can do a lot. Usually prefer awk if the data has fields. sed is particularly good for find and replace.

Use perl if a very large program.

It is often more powerful if you can combine commands within a shell script.

Try to use something that you understand well, and try to write in a simple manner where the logic is clear.
This User Gave Thanks to hanson44 For This Post:
Prathmesh
 

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Implementing MORE,HEAD & TAIL

hai in my shell script i want to replace the following commands 1) more 2) head 3) tail i want to try all type of possible options avaliabul in the above commands please help in implementing those commands (9 Replies)
Discussion started by: g_s_r_c
9 Replies

2. UNIX for Dummies Questions & Answers

head & tail

I've a major file which includes other files and now I wanna 'cut' the file in several minor parts....like .... find / -name "*.tmp" >filea wc -l filea >fileb sed -e '1s/ filea//' fileb >filec AMOUNT=`cat filec` if ; then cat file a |head -100l (ell) |tail -100l >filec cat file a |head... (6 Replies)
Discussion started by: svennie
6 Replies

3. Shell Programming and Scripting

Head and Tail in One Line

I am new to UNIX......I have one file which contains thousnads of records with header and tailer. Header Record 1 Record 2 .... .... Last Record Trailer I want to concatenate Header and Trailer in the first line....now the output should look like this: Header: Header value, Trailer:... (2 Replies)
Discussion started by: 33junaid
2 Replies

4. Shell Programming and Scripting

Imitate head and tail command script

Hi, I have been given assignment of 30 scripts out of which I was able to solve many, I need help with few out of which one asks to imitate head and tail command of unix without using the head and tail commands. Problem is stated below: Write an interactive shell script to imitate the head... (5 Replies)
Discussion started by: nutalk
5 Replies

5. Shell Programming and Scripting

Averaging in increments using awk & head/tail

Hi, I only have a very limited understanding and experience with writing code and I was hoping I could get some help. I have a dataset of two columns (txt format, numbers in each row separated by a tab) Eg. 1 5 2 5 3 6 4 7 5 6 6 6 7 ... (5 Replies)
Discussion started by: Emred_Skye
5 Replies

6. Shell Programming and Scripting

head / tail combination returns multiple rows

Hi, As part of our project, we need to load historical data for a year before our system is live. We have the data feed files that we need to load. However, I need to make sure that the file structure (number of fields separated by a comma) on the field is same for all the files of the same... (1 Reply)
Discussion started by: raj.jha
1 Replies

7. UNIX for Dummies Questions & Answers

head\tail how to display middle lines

hay i need to display middle line: 1 2 3 4 5 how can i display 3-4? (6 Replies)
Discussion started by: margan_ron
6 Replies

8. Homework & Coursework Questions

Head Tail Problem

Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted! 1. The problem statement, all variables and given/known data: view the 7th line of the program xxx.sh 2. Relevant commands, code, scripts, algorithms: head command tail... (10 Replies)
Discussion started by: hbell221
10 Replies

9. Homework & Coursework Questions

How to display certain line of file only using head or tail in 1 command?

First month learning about the Linux terminal and it has been a challenge yet fun so far. We're learning by using a gameshell. I'm trying to display a certain line ( only allowed 1 command ) from a file only using the head or tail. I'm pretty about this answer: head -23 history.txt | tail -1... (1 Reply)
Discussion started by: forzatekk
1 Replies

LEARN ABOUT SUNOS

largefile

largefile(5)						Standards, Environments, and Macros					      largefile(5)

NAME

       largefile - large file status of utilities

DESCRIPTION

       A  large file is a regular file whose size is greater than or equal to 2 Gbyte ( 2**31 bytes). A small file is a regular file whose size is
       less than 2 Gbyte.

   Large file aware utilities
       A utility is called large file aware if it can process large files in the same manner as it does small files. A utility that is large  file
       aware is able to handle large files as input and generate as output large files that are being processed. The exception is where additional
       files  are used as system configuration files or support files that can augment the processing. For example, the file utility supports  the
       -m  option  for	an  alternative "magic" file and the -f option for a support file that can contain a list of file names. It is unspecified
       whether a utility that is large file aware will accept configuration or support files that are large files. If a large file  aware  utility
       does  not accept configuration or support files that are large files, it will cause no data loss or corruption upon encountering such files
       and will return an appropriate error.

       The following /usr/bin utilities are large file aware:

       adb	     awk	   bdiff	 cat	       chgrp
       chmod	     chown	   cksum	 cmp	       compress
       cp	     csh	   csplit	 cut	       dd
       dircmp	     du 	   egrep	 fgrep	       file
       find	     ftp	   getconf	 grep	       gzip
       head	     join	   jsh		 ksh	       ln
       ls	     mdb	   mkdir	 mkfifo        more
       mv	     nawk	   page 	 paste	       pathchck
       pg	     rcp	   remsh	 rksh	       rm
       rmdir	     rsh	   sed		 sh	       sort
       split	     sum	   tail 	 tar	       tee
       test	     touch	   tr		 uncompress    uudecode
       uuencode      wc 	   zcat

       The following /usr/xpg4/bin utilities are large file aware:

       awk	     cp 	   chgrp	 chown	       du
       egrep	     fgrep	   file 	 grep	       ln
       ls	     more	   mv		 rm	       sed
       sh	     sort	   tail 	 tr

       The following /usr/xpg6/bin utilities are large file aware:

       getconf	     ls 	   tr

       The following /usr/sbin utilities are large file aware:

       install	     mkfile	   mknod	 mvdir	       swap

       See the USAGE section of the swap(1M) manual page for limitations of swap on block devices greater than 2 Gbyte on a 32-bit operating  sys-
       tem.

       The following /usr/ucb utilities are large file aware:

       chown	     from	   ln		 ls	       sed
       sum	     touch

       The /usr/bin/cpio and /usr/bin/pax utilities are large file aware, but cannot archive a file whose size exceeds 8 Gbyte - 1 byte.

       The /usr/bin/truss utilities has been modified to read a dump file and display information relevant to large files, such as offsets.

   cachefs file systems
       The following /usr/bin utilities are large file aware for cachefs file systems:

       cachefspack	cachefsstat

       The following /usr/sbin utilities are large file aware for cachefs file systems:

       cachefslog	cachefswssize	cfsadmin	 fsck
       mount		umount

   nfs file systems
       The following utilities are large file aware for nfs file systems:

       /usr/lib/autofs/automountd    /usr/sbin/mount
       /usr/lib/nfs/rquotad

   ufs file systems
       The following /usr/bin utility is large file aware for ufs file systems:

	      df

       The following /usr/lib/nfs utility is large file aware for ufs file systems:

	      rquotad

       The following /usr/xpg4/bin utility is large file aware for ufs file systems:

	      df

       The following /usr/sbin utilities are large file aware for ufs file systems:

       clri	     dcopy	   edquota	 ff	       fsck
       fsdb	     fsirand	   fstyp	 labelit       lockfs
       mkfs	     mount	   ncheck	 newfs	       quot
       quota	     quotacheck    quotaoff	 quotaon       repquota
       tunefs	     ufsdump	   ufsrestore	 umount

   Large file safe utilities
       A  utility  is called large file safe if it causes no data loss or corruption when it encounters a large file. A utility that is large file
       safe is unable to process properly a large file, but returns an appropriate error.

       The following /usr/bin utilities are large file safe:

       audioconvert	audioplay    audiorecord    comm	  diff
       diff3		diffmk	     ed 	    lp		  mail

       mailcompat	mailstats    mailx	    pack	  pcat
       red		rmail	     sdiff	    unpack	  vi
       view

       The following /usr/xpg4/bin utilities are large file safe:

       ed	     vi 	   view

       The following /usr/xpg6/bin utility is large file safe:

       ed

       The following /usr/sbin utilities are large file safe:

       lpfilter      lpforms

       The following /usr/ucb utilities are large file safe:

       Mail	     lpr

       The following /usr/lib utility is large file safe:

	      sendmail

SEE ALSO

       lf64(5), lfcompile(5), lfcompile64(5)

SunOS 5.10							    7 Nov 2003							      largefile(5)
All times are GMT -4. The time now is 02:37 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy