Remove empty lines in a text file via grep

Question

FILE   hello  world  foo  bar   How can I remove all the empty new lines in this FILE   Output of command   FILE   hello world foo bar

User · Answer

Try this  sed -i       t    d  file-name  It will delete all blank lines having any no  of white spaces  spaces or tabs  i e   0 or more  in the file   Note  there is a  space  followed by   t  inside the square bracket   The modifier -i will force to write the updated contents back in the file  Without this flag you can see the empty lines got deleted on the screen but the actual file will not be affected

User · Answer

Simplest Answer -----------------------------------------  root node1     cat  etc sudoers   grep -v -e    -e    Defaults    visiblepw Defaults    always set home Defaults    match group by gid Defaults    always query group plugin Defaults    env reset Defaults    env keep     quot COLORS DISPLAY HOSTNAME HISTSIZE KDEDIR LS COLORS quot  Defaults    env keep     quot MAIL PS1 PS2 QTDIR USERNAME LANG LC ADDRESS LC CTYPE quot  Defaults    env keep     quot LC COLLATE LC IDENTIFICATION LC MEASUREMENT LC MESSAGES quot  Defaults    env keep     quot LC MONETARY LC NAME LC NUMERIC LC PAPER LC TELEPHONE quot  Defaults    env keep     quot LC TIME LC ALL LANGUAGE LINGUAS  XKB CHARSET XAUTHORITY quot  Defaults    secure path    sbin  bin  usr sbin  usr bin root    ALL  ALL        ALL  wheel  ALL  ALL        ALL  root node1

User · Answer

grep       my file  example  THIS  IS  THE  FILE  EOF MYFILE   it gives as output only lines with at least 2 characters   THIS IS THE FILE EOF MYFILE   See also the results with grep     my file outputs  THIS  IS  THE  FILE  EOF MYFILE   and also with grep      my file outputs  THIS IS THE FILE EOF MYFILE

User · Answer

Here is a solution that removes all lines that are either blank or contain only space characters   grep -v      space       foo txt

User · Answer

Try ex-way   ex -s   v  S d  -cwq test txt   For multiple files  edit in-place    ex -s   bufdo v  S d  -cxa   txt   Without modifying the file  just print on the standard output    cat test txt   ex -s   v  S d    p  q   dev stdin

User · Answer

with awk  just check for number of fields  no need regex    more file hello  world  foo  bar    awk  NF  file hello world foo bar

User · Answer

If you want to know what the total lines of code is in your Xcode project and you are not interested in listing the count for each swift file then this will give you the answer   It removes lines with no code at all and removes lines that are prefixed with the comment    Run it at the root level of your Xcode project  find      -iname    swift    -exec grep -v      space            grep -v -e        wc -l  If you have comment blocks in your code beginning with    and ending with    such as      This is an comment block      then these will get included in the count    Too hard

User · Answer

grep   FILE     And if you really want to do it in sed  then  sed -e     d FILE    And if you really want to do it in awk  then  awk     FILE

User · Answer

Perl might be overkill  but it works just as well   Removes all lines which are completely blank   perl -ne  print if      file   Removes all lines which are completely blank  or only contain whitespace   perl -ne  print if      s     file   Variation which edits the original and makes a  bak file   perl -i bak -ne  print if      s     file

User · Answer

Try the following   grep -v -e

User · Answer

If removing empty lines means lines including any spaces  use   grep   S  FILE   For example      printf  line1 n nline2 n  nline3 n t nline4 n   gt  FILE    cat -v FILE line1  line2  line3  line4    grep   S  FILE line1 line2 line3 line4    grep   FILE line1 line2  line3  line4     See also    How to remove empty blank lines  including spaces  in a file in Unix  How to remove blank lines from a file in shell  With sed  Delete empty lines using sed With awk  Remove blank lines using awk

[linux] Remove empty lines in a text file via grep

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