Bash Strip trailing linebreak from output

Question

When I execute commands in Bash  or to be specific  wc -l  lt  log txt   the output contains a linebreak after it  How do I get rid of it

User · Answer

If you assign its output to a variable  bash automatically strips whitespace   linecount  wc -l  lt  log txt

User · Answer

There is also direct support for white space removal in Bash variable substitution   testvar   wc -l  lt  log txt  trailing space removed   testvar     space     leading space removed   testvar     space

User · Answer

If your expected output is a single line  you can simply remove all newline characters from the output  It would not be uncommon to pipe to the tr utility  or to Perl if preferred  wc -l  lt  log txt   tr -d   n   wc -l  lt  log txt   perl -pe  chomp   You can also use command substitution to remove the trailing newline  echo -n  quot   wc -l  lt  log txt  quot   printf  quot  s quot   quot   wc -l  lt  log txt  quot    If your expected output may contain multiple lines  you have another decision to make  If you want to remove MULTIPLE newline characters from the end of the file  again use cmd substitution  printf  quot  s quot   quot    lt  log txt  quot   If you want to strictly remove THE LAST newline character from a file  use Perl  perl -pe  chomp if eof  log txt   Note that if you are certain you have a trailing newline character you want to remove  you can use head from GNU coreutils to select everything except the last byte  This should be quite quick  head -c -1 log txt  Also  for completeness  you can quickly check where your newline  or other special  characters are in your file using cat and the  show-all  flag -A  The dollar sign character will indicate the end of each line  cat -A log txt

User · Answer

If you want to print output of anything in Bash without end of line  you echo it with the -n switch  If you have it in a variable already  then echo it with the trailing newline cropped    testvar   wc -l  lt  log txt    echo -n  testvar  Or you can do it in one line  instead    echo -n   wc -l  lt  log txt

User · Answer

If you want to remove only the last newline  pipe through   sed -z    s  n       sed won t add a  0 to then end of the stream if the delimiter is set to NUL via -z  whereas to create a POSIX text file  defined to end in a  n   it will always output a final  n without -z   Eg       echo foo  echo bar      sed -z    s  n      echo tender foo bartender   And to prove no NUL added       echo foo  echo bar      sed -z    s  n       xxd 00000000  666f 6f0a 6261 72                        foo bar     To remove multiple trailing newlines  pipe through   sed -Ez    s  n

User · Answer

One way   wc -l  lt  log txt   xargs echo -n

User · Answer

printf already crops the trailing newline for you       printf   s    wc -l  lt  log txt    Detail    printf will print your content in place of the  s string place holder    If you do not tell it to print a newline   s n   it won t

[bash] Bash: Strip trailing linebreak from output

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