replacing a line of file with a line from another file

[mahesh_24]

Can anybody let me know how to replace a line by (line to be searched by pattern ) with another line which is available in another file.

[Mark Grant]

something like

#!/bin/sh
LINE2=$(grep "line I need" file2)
sed "s/pattern/$LINE2/" file1 > file3

[mahesh_24]

Hi Mark,
i have tried that usind sed but the error which i am getting is that pattern canot be parsed.The problem is
I have one of the user entries in passwd file ( all the 7 fields ) in one passwd file
say
oracledb:*:11:11::/var/spool/uucppublic:/usr/lbin/uucp/uucico

Now i have constructed a line

Xoracleb:*NP* :11:11:user disabled :/var/spool/uucppublic:/bin/false

using script now i wanna replace the constructed line which is there in my o/p file with the line matching "^oracledb" in the start of the line .
Note:I do not want to replace just "oracledb "

I guess sed gave me the error because the variable was long
i tried the following using sed


sed ' /'$orgvar`/ {
s/'$orgvar'/'$newvar'/
}' datafile

where $orgvar contains the old line and $newvar contains the new line which has to come in place of old line

[Jean-Luc Oudart]

with special characters this might be a bit tricky

In a previous thread I mentioned the use of vi
have a look at it :
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x38fa82eced96bc409e0e67b4869c642d,00.html

Rgds,
JL

[mahesh_24]

Hi Jean , i read the same and have one question

is there a way to parse a shell variable in vi with can be given as $var for search patterns

[Rodney Hills]

Using "awk" you could search for lines that match $orgvar and print $newvar instead-

awk -Vorg="$orgvar" -Vnew="$newvar" '{if $0 == $org then print $new else print $0}' newpasswd

Not sure your full intent here. Are you planning on changing multiple passwd files or are their multiple entries within one passwd file.

HTH

-- Rod Hills

[Jean-Luc Oudart]

I think you may still have the problem as long as you have special characters.
Same apply to awk.

Therefore, as mentioned in the previous thread thr "trick" is to position the cursor in the file and import an external file.

Rgds,
Jean-Luc

[Fredrik Acosta]

Since the search pattern contains slashes '/' you can't use '/' for expression delimiter with sed - try to use another character (e.g. '@').

Example:
sed 's@find@replace@' < file1 > file2

To replace a line in one file with a line from another file - try:

(With sed)
----
#!/bin/sh

# 'file' is the file to be changed
# 'template' is a file containing strings to replace with
# 'find' is the string to search for
# 'repl' is part of the string to replace with

find=$1; template=$2; find=$3; repl=$4

replace=`grep "$repl" $template`
sed "/$find/s@@$replace@" $file > /tmp/$file.$$
mv /tmp/$file.$$ $file
----
invoke as:
script '^oracledb' '^Xoracleb'

Better is to use 'ed' (if you use the above method, you might lose permission settings on the original file depending on umask settings).

(with ed)
----
#!/bin/sh

file=$1; template=$2; find=$3; repl=$4
replace=`grep "$repl" $template`

ed - $file </$find/c
$replace
.
w
de
----

Happy scripting!

[Dave La Mar]

Mahesh -
sed indeed will error out if / is in the string.
I have successfully done this by simply escaping the / with a \ in the string.
i.e. string="\/home\/someone\/or_something"

Best of luck.

Regards,

dl