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Linuxnoobie123 10-11-2012 12:27 AM

Linux command help
 
Hi there
I'm new to this forum:
I was wondering if someone could help me figure out a task

In the second field, change 'f' to female and 'm' to male globally. Display the first 9 lines.

Use 2 sed statements one piped to another.
Note use of single quotes in examples.

This was my output

[sjim7@hills ~]$ grep -k2 |sed 's/m/male/g' famous.data | sed 's/f/female/g' | head -n 9
grep: invalid option -- 'k'
Usage: grep [OPTION]... PATTERN [FILE]...
Try `grep --help' for more information.
01 male maleotzart amaleadeous 25 2nd 94233
02 male guthrie woody 23 2nd 94223
03 female simaleone nina 27 2nd 94112
04 male lennon john 29 2nd 94221
05 female harris emalemaleylou 20 2nd 94222
06 male malearley bob 22 2nd 94112
07 female malearley rita 26 2nd 94212
08 female warwick dione 26 2nd 94222
09 male prine john 35 3rd 94321

How would i type it to focus on the second column to change the m to males, and f to females , instead of changing every letter in each column that has a m to male , thanks

pan64 10-11-2012 12:54 AM

duplicate of https://www.linuxquestions.org/quest...em-4175431599/

markush 10-11-2012 01:04 AM

Hi, you should post the sourcedata as well. Probably it looked like that:
Code:

01 m motzart amadeous 25 2nd 94233
02 m guthrie woody 23 2nd 94223
03 f simone nina 27 2nd 94112
04 m lennon john 29 2nd 94221
05 f harris emmylou 20 2nd 94222
06 m marley bob 22 2nd 94112
07 f marley rita 26 2nd 94212
08 f warwick dione 26 2nd 94222
09 m prine john 35 3rd 94321

But your problem is that you search for any f and any m, but you'll have to search only for single letters f and m. But in your case it seems easier, don't use the g option since it substitutes any f or m on a line, without g it substitutes only the first occurence of the letter.
Code:

sed -n s/f/female/ p
should work for you.

Markus

Linuxnoobie123 10-11-2012 01:16 AM

Hey Markus,
Sorry, but i tried replacing that command that you stated above, it doesn't work
Do you mind copying and pasting the command below , thanks

[sjim7@hills ~]$ grep -k2 |sed 's/m/male/g' famous.data | sed 's/f/female/g' | head -n 9

markush 10-11-2012 05:35 AM

Well, when I put the data into a file data.txt with the content
Code:

01 m motzart amadeous 25 2nd 94233
02 m guthrie woody 23 2nd 94223
03 f simone nina 27 2nd 94112                                                   
04 m lennon john 29 2nd 94221                                                   
05 f harris emmylou 20 2nd 94222                                                 
06 m marley bob 22 2nd 94112                                                     
07 f marley rita 26 2nd 94212                                                   
08 f warwick dione 26 2nd 94222                                                 
09 m prine john 35 3rd 94321

I get this output:
Code:

markus@samsung:~$ sed -n 's/f/female/ p' < data.txt
03 female simone nina 27 2nd 94112
05 female harris emmylou 20 2nd 94222
07 female marley rita 26 2nd 94212
08 female warwick dione 26 2nd 94222

If you want more help, please post the file with your complete data to help us trying it out.

You should try
Code:

grep -k2 |sed -n 's/m/male/ p' famous.data | sed -n 's/f/female/ p' | head -n 9
Markus

overlook 10-12-2012 01:46 PM

I'm a bit tired so I can't think of a better solution atm. but this script should do what you want. I'm sure there are better, more elegant, ways though.
Code:

#!/bin/bash

if [ -z $1 ]; then
  echo "syntax: $0 <filename>"
  exit 1
fi
IFS=" "
while read f1 f2 f3 f4 f5 f6 f7 ; do
 if [ $f2 = "m" ]; then
  f2=male
 elif [ $f2 = "f" ]; then
  f2=female
 fi
 echo $f1 $f2 $f3 $f4 $f5 $f6 $f7
done < $1

Used as such:
Code:

script.sh famous.data

David the H. 10-13-2012 11:42 AM

Please use ***[code][/code]*** tags around your code and data, to preserve the original formatting and to improve readability. Do not use quote tags, bolding, colors, "start/end" lines, or other creative techniques.

Markush's sed expression should be fine. If you would post the actual command you used and what you actually got in return instead of just saying "it didn't work", we might be able to figure out why.

In any case, one big problem you have is the first part of your command chain:

Code:

grep -k2 |sed 's/m/male/g' famous.data
sed can take input from either a file, or from a pipe, but not both at once. And your grep command doesn't have any input, nor does it have a "-k" option. Could you explain what you're trying to do here? I imagine the rest of it will work if you leave the grep out.

Finally, since your assignment says to use two sed commands you have to do it that way, but actually the whole thing, including the function of head, can be completed with a single, relatively easy sed command (a single two-part address and two sub-expressions).

I'll leave it up to you to figure out the details.

Here are a few useful sed references:
http://www.grymoire.com/Unix/Sed.html
http://sed.sourceforge.net/grabbag/
http://sed.sourceforge.net/sedfaq.html
http://sed.sourceforge.net/sed1line.txt


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