doubt in sed cmd

Code:

sed 's/lamb$/ham/' sed.txt

this code didn work for me...y??

[335723@oracleclient ~]$ cat sed.txt
mary had a lamb
jack ate a sapm sandwich
jill had a ham ham spamwich

[335723@oracleclient ~]$ sed 's/lamb$/ham/' sed.txt
mary had a ham
jack ate a sapm sandwich
jill had a ham ham spamwich


it works....

I tried this. Its not working for me

sed 's/a$/z/' cp.txt
hw r u
mary had a little lamb.
jill had a lamb sandwich


no change occurs in content....it doesnt work.

$ - it changes the character or string only if it occurs at the end of d line(last word in a line)....

sed 's/u$/z/' cp.txt
hw r z
mary had a little lamb.
jill had a lamb sandwich

sed 'y/a/z/' dd.txt

this ll work if u try to change single character 'a' ....
''y " is used to change single char....
here a will be replaced by z....

[335818@oracleclient ~]$ sed 's/a/z/' cp.txt
hw r u
mzry had a little lamb.
jill hzd a lamb sandwich


Is this the desired output ? If so, its working

yea ...
here s stands for substitution ....

for further reference in "sed",check t topic "unix cmd doubt"....

$ to substitute if the string is in end of the line
^ to substitute if the string is in begining of the line

the first time when i used

Code:

sed 's/lamb$/ham/' sed.txt

it didn work...and now its working... y s t so??

its workin right .. leave it..

but wats the difference in specifying it as lamb and lamb$ ??
both works

[335723@oracleclient ~]$ cat aaa.txt
mlamb lambd
dhhdh dfdd
lamb lamb
ggg lambder

[335723@oracleclient ~]$ sed 's/lamb/ssss/g' aaa.txt
mssss ssssd
dhhdh dfdd
ssss ssss
ggg ssssder

[335723@oracleclient ~]$ sed 's/lamb$/ssss/g' aaa.txt
mlamb lambd
dhhdh dfdd
lamb ssss
ggg lambder


check out diff by urself...........

is it that lamb$ replaces exactly the word lamb???
if so why not the first lamb in the third line??

lamb$ replaces all lines ending with lamb,whereas lamb replaces all lambs

it replaces only the lamb tat occurs as the last word in a particular line

cat > sed.txt
mlamb lambd
ddss
lamb lamb
ggg lambg

sed 's/lamb$/ham/' sed.txt
mlamb lambd
ddss
lamb ham
ggg lambg

sed 's/lamb/ham/' sed.txt
mham lambd
ddss
ham lamb
ggg hamg

sed 's/lamb/ham/g' sed.txt
mham hamd
ddss
ham ham
ggg hamg

sed 's/lamb$/ham/g' sed.txt
mlamb lambd
ddss
lamb ham
ggg lambg

these r the things that i tried out..these r all the possible combinations that i can think of..check it out...

[335723@oracleclient ~]$ cat aaa.txt
mlamb lambd
dhhdh dfdd
lamb lamb lamb
lamb lamb
lamb hell
ggg lambde
r
[335723@oracleclient ~]$ sed 's/lamb$/zzzz/g' aaa.txt
mlamb lambd
dhhdh dfdd
lamb lamb zzzz
lamb lamb
lamb hell
ggg lambde
r

wat abt t 4th line

$ sed 's/lamb$/zzzz/g' aaa.txt will replace 'lamb' with 'zzzz'if a line ends with lamb.
$ sed 's/^lamb/zzzz/g' aaa.txt will replace 'lamb' with 'zzzz' if a line starts with lamb.

It is working fine. Check is there any extra space after 'lamb' in 4th line.

@anand
did u try??

yeah it works....
and on using lamb$
even if the last word in line is "mylamb" , it ll be replaced as "myzzzz"

No.... $ means it replaces the word oly wen it occurs at the end..

yup...

@deepika

anand also trying to say the same.