UNIX for Dummies Questions & Answers

What is the appropriate command should i use to insert a character(example A) in front of line 1 to line 200...Pls help

793589,

Try this:

Code:

:1,200s/^/A/

Regards,
Davf

Thanks..
Is workable.

How about if i need to replace a character in the middle of sentence from line 10 to 50?

exmaple, i need to replace the number "5" from all lines below with "X"?
What is the useful vim command that i can apply for..

ddpadsgag506xghssuyj
ddpadsgag546xghssuys
ddsadsgag596xghssuy_te
ddsadsgag506xghssuy_pe
ddsadsgag526xghssuys
ddsadsgag506ighssuys
ddsadsgag506pghssuyk

to replace number 5 with X in lines 10 to 50:

Code:

:10,50s/5/X/

Yes, thanks many & very appreciate that..
By the way, what if i've a various numeric number at all the line in my file and i just intend to replace the 1st digit only with character "X". Example,

my file
ddpadsgag506xghssuyj_3#ods
ddpadsga446xghssuys_47#523
ddsadsgagh396xghssuy_te_3.4
ddsadsgag506xghssuy_pe_3.35
ddsadsgag326xghssuys
ddsadsgag506ighssuys_eng
ddsadsgag506pghssuyk

result
ddpadsgagX06xghssuyj_3#ods
ddpadsgaX46xghssuys_47#523
ddsadsgaghX96xghssuy_te_3.4
ddsadsgagX06xghssuy_pe_3.35
ddsadsgagX26xghssuys
ddsadsgagX06ighssuys_eng
ddsadsgagX06pghssuyk

And what command should i apply to eliminate the content after _3 at end of the line. Example,

my file
ddpadsgagX06xghssuyj_3#ods
ddsadsgaghX96xghssuy_te_3.4
ddsadsgagX06xghssuy_pe_3.35

result
ddpadsgagX06xghssuyj_3
ddsadsgaghX96xghssuy_te_3
ddsadsgagX06xghssuy_pe_3

try this (i haven't tried myself):

Code:

perl -pi -e 's/(\d)(\d\d)/X\2/'

try this (i haven't tried myself):

Code:

perl -pi -e 's/_3(.*)$/_3/'

Using sed command:

Code:

 sed 's/[0-9]/X/; s/_3.*$/_3/' yourfile

It works with your sample I/O