Sponsored Content
Top Forums UNIX for Beginners Questions & Answers Usage of sed, position of apostrophe Post 303022811 by Aia on Friday 7th of September 2018 01:16:17 PM
Old 09-07-2018
Quote:
Originally Posted by baris35
Hello,
I have never ever seen below notation for string substitution.

Code:
sed -i -e 's/tttt/pppp'/g /var/bin/czech.sh;

The strange thing for me is the position of the apostrophe. Should it be before the / or after the g?
If I had been writing that command line, I would have chosen below way:
Code:
sed -i -s 's/tttt/pppp/g' /var/bin/czech.sh

Could you please explain what it differs...
Is that about the operating system?

Many thanks
Boris
Regular expressions uses meta-characters. These are characters that have special meaning beyond the representation of the character. The shell has also meta-characters. Therefore in order to protect the meaning of these characters it must be quoted so it gets passed to sed as the regular expression intended.
In this case the quoting could be avoided all together sed s/tttt/pppp/g /var/bin/czech.sh since there are no meta-characters.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

translate text (1 position) with sed

Hello, I'm trying to translate a fixed length (the first 6 positions) that begins with a 0 to overwrite the field with an *. Any suggestion? File 1 ------- 013344 01:20 222343 19:30 233333 20:30 File 2 (result) ----------------- ****** 01:20 222343 19:30 233333 20:30 (5 Replies)
Discussion started by: peterk
5 Replies

2. HP-UX

how can I find cpu usage memory usage swap usage and logical volume usage

how can I find cpu usage memory usage swap usage and I want to know CPU usage above X% and contiue Y times and memory usage above X % and contiue Y times my final destination is monitor process logical volume usage above X % and number of Logical voluage above can I not to... (3 Replies)
Discussion started by: alert0919
3 Replies

3. Shell Programming and Scripting

How to replace symbols by position using SED

Hi all, I need your help. For example I have string in file.txt: -x -a /tmp/dbarchive_NSS_20081204 -f 900 -l 1 2008/12/04 2008/12/04 So, I need to replace symbols from (for e.g.) position 26 till 33 with symbols which I have in file replace.txt And I have no idea how to do it. If... (1 Reply)
Discussion started by: nypreH
1 Replies

4. Shell Programming and Scripting

Remove text from n position to n position sed/awk

I want to remove text from nth position to nth position couple of times in same line my line is "hello is there anyone can help me with this question" I need like this ello is there anyone can help me with question 'h' is removed and 'this' removed from the line. I want to do this... (5 Replies)
Discussion started by: elamurugu
5 Replies

5. Shell Programming and Scripting

Sed position specific replace

I'm drawing a blank on how to use sed to replace selectively based on position in the string (vs nth occurence): hello.|there.|how.|are.|you.| I want the period removed in the 3rd item (as defined by the pipe delimiter) if a period is present. So the result in this case would be: ... (2 Replies)
Discussion started by: tiggyboo
2 Replies

6. Shell Programming and Scripting

Replace apostrophe with backslash apostrophe

I'm coding using BASH and have a requirement to replace apostrophes with backslash apostrophes. For example below: I am here 'in my room' ok Would be changed to: I am here /'in my room/' ok The original text is coming from a field in a MySql database and is being used by another process that... (5 Replies)
Discussion started by: dbjock
5 Replies

7. Programming

How to change only one occurance of apostrophe with sed

Hi, I have a document with usual English text and some of the words have apostrophes (e.g. don't, can't, etc.) I would like all these apostrophes to be doubled (e.g. don''t, can''t, etc.), but the problem is, that some of such words have double apostrophe and by using sed -i "s/'/''/g"... (2 Replies)
Discussion started by: neptun79
2 Replies

8. Shell Programming and Scripting

Trying to move a column into another position within a sed script

Currently the table looks like this student-id,last,first,hwk1,hwk2,hwk3,exam1,hwk4,hwk5,exam2 pts-avail,,,100,150,100,200,100,150,300 991-78-7872,Thompson,Ken,95,143,79,185,95,135,259 123-45-6789,Richie,Dennis,99,123,89,189,97,139,279 234-56-7891,Aho,Al,78,146,75,176,88,128,285... (3 Replies)
Discussion started by: ertang
3 Replies

9. Shell Programming and Scripting

awk usage for position matching

i have a requirement like this if the line contains from position 294 to 299 is equal to "prabhu" ,then print entire line . i want to use awk awk '{if(substr(294-299) == 'prabhu') print "line" }' filename (1 Reply)
Discussion started by: ptappeta
1 Replies

10. UNIX for Dummies Questions & Answers

Using sed to insert at position x and then every interval y for each line

Thanks to help from Don Cragun in post 302924174, I'm off and getting into trouble on my own (finally) with sed. Here is my goal - insert \\r\n at the 60th character on each line and then every 76th character thereafter: Input:... (3 Replies)
Discussion started by: gusbrown
3 Replies
TR(1)							      General Commands Manual							     TR(1)

NAME
tr - translate characters SYNOPSIS
tr [ -cds ] [ string1 [ string2 ] ] DESCRIPTION
Tr copies the standard input to the standard output with substitution or deletion of selected characters (runes). Input characters found in string1 are mapped into the corresponding characters of string2. When string2 is short it is padded to the length of string1 by dupli- cating its last character. Any combination of the options -cds may be used: -c Complement string1: replace it with a lexicographically ordered list of all other characters. -d Delete from input all characters in string1. -s Squeeze repeated output characters that occur in string2 to single characters. In either string a noninitial sequence -x, where x is any character (possibly quoted), stands for a range of characters: a possibly empty sequence of codes running from the successor of the previous code up through the code for x. The character followed by 1, 2 or 3 octal digits stands for the character whose 16-bit value is given by those digits. The character sequence followed by 1, 2, 3, or 4 hexadecimal digits stands for the character whose 16-bit value is given by those digits. A followed by any other character stands for that character. EXAMPLES
Replace all upper-case ASCII letters by lower-case. tr A-Z a-z <mixed >lower Create a list of all the words in one per line in where a word is taken to be a maximal string of alphabetics. String2 is given as a quoted newline. tr -cs A-Za-z ' ' <file1 >file2 SOURCE
/sys/src/cmd/tr.c SEE ALSO
sed(1) TR(1)
All times are GMT -4. The time now is 04:22 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy