1. Shell Programming and Scripting

Hi, Could you please explain me the below statement -- phrase wise. sed -e :a -e '$q;N;'$cnt',$D;ba' abc.txt > xyz.txt if suppose $cnt contains value: 10 it copies last 9 lines of abc.txt to xyz.txt why it is copying last 9 rather than 10. and also what is ba and $D over there in... (4 Replies)

2. Shell Programming and Scripting

Hi, The following command works fine for me, but I could not grasp the logic working behind of sed command, it's obscure to me :( :confused: echo "./20080916/core/audioex.amr" | sed "s%\(\)/%\1_%g" o/p: ./20080916_core_audioex.amr Could anyone please explain to me in detail, that how... (6 Replies)

3. Shell Programming and Scripting

Hello everyone, I found this command line in a website: perl -pi.bak -we's/\z/Your new line\n/ if $. == 2;' your_text_file.txt With this command line you can insert a new line anywhere you want in a text without overwriting what's in it. -p causes perl to assume a loop around your... (4 Replies)

4. Shell Programming and Scripting

This is my first post so hi to you all. I have browsed these forums in the past and what a great community and resource this is! Thanks to all the contributors ... I look forward to being able to give something back. In the meantime, I have a little conundrum concerning sed. My very simple... (6 Replies)

5. UNIX for Dummies Questions & Answers

Hi Friends, I am trying to modify a script .The script contains this line: sed -n -e 's_.*>\(.*\)<.*_\1_p' filename.xml I am not great in sed command.I know, it is regular expression to match a pattern string that starts with s_ and ends with 1_.I doesnot give the desired result. Can... (4 Replies)

6. Shell Programming and Scripting

sed '$!N; /^\(.*\)\n\1$/!P; D' i found this file which removes duplicates irrespective for sorted or unsorted file. keep first occurance and remove the further occurances. can any1 explain how this is working.. i need to remove duplicates following file. duplicate criteria is not the... (3 Replies)

7. UNIX for Advanced & Expert Users

can anyone please tell me what does this expression means , i am under probation and need some explanation :) $AUDIT_DIR -type f -mtime +$AUDIT_EXPIRE \ -exec rm {} > /dev/null 2>&1 \; AUDIT_DIR="/var/log/" AUDIT_EXPIRE='30' Please use code tags! (4 Replies)

8. UNIX for Dummies Questions & Answers

Hi everyone, I am wondering if someone could please break down and explain the following sort command for me: ls ${DEST_LOCATION}/${FILES} | sort -rt -k 4,4n | head -1 I have tried working it out using 'man sort', but on AIX there is not a great explanation of this function. I know that... (9 Replies)

9. Shell Programming and Scripting

Will someone give me an explanation on how the sed command below works. sed 's/.*//' Thanks! (3 Replies)

10. UNIX for Beginners Questions & Answers

Hi Folks, I am struggling to understand nawk command which was used by another developer. Can you please explain what each character or string is doing here below: if ; then (3 Replies)