I used sed to change a word, the file is now erased -

I used sed to change a word, the file is now erased -

i utilize sed command alter cis132 cis132 introduction unix/linux. did:

sed 's/cis132/cis132 introduction unix\/linux/g' cised

i got command prompt figured set. cat cised , got no output. happened there? can contents somehow erased?

thanks

jason

maybe did this:

sed 's/cis132/cis132 introduction unix\/linux/g' cised > cised

.. , that's not way create replacement --in-place. right way is:

sed --in-place 's/cis132/cis132 introduction unix\/linux/g' cised what happened there?

you redirect standard output new empty file called cised (you used >). erases content in file.

can contents somehow erased?

you can't. replaced empty file.

extracted comment:

this shell history:

971 cat cised 972 grep 'cis132' | sed 's/cis132/cis132 introduction unix/linus/g' cised 973 sed '1,2s/cis132/cis132 introduction unix/linus/g' cised 974 sed '1,3s/cis132/cis132 introduction unix"/"linus/g' cised 975 sed 's/cis132/cis132 introduction unix/linux/g' > cised 976 sed 's/cis132/cis132 introduction unix/linux/g' cised 977 sed 's/cis132/cis132 introduction unix'/'linux/g' cised 978 sed 's/cis132/cis132 introduction unix\/linux/g' cised 979 cat cised 980 cat cised 981 ls 982 cat cised

in 971 read content , there. then, in 975 though command fails, redirection operator (>) creates new empty file called cised , that's moment when file erased.

sed