How to specify more spaces for the delimiter using cut

Question

Is there any way to specify a field delimiter for more spaces with the cut command   like         For example  In the following string  I like to reach value  3744   what field delimiter I should say    ps axu   grep jboss  jboss     2574  0 0  0 0   3744  1092          S    Aug17   0 00  bin sh  usr java jboss bin run sh -c example com -b 0 0 0 0   cut -d    is not what I want  for it s only for one single space   awk is not what I am looking for either  but how to do with  cut    thanks

User · Accepted Answer

Actually awk is exactly the tool you should be looking into   ps axu   grep   j boss    awk   print  5     or you can ditch the grep altogether since awk knows about regular expressions   ps axu   awk    j boss   print  5     But if  for some bizarre reason  you really can t use awk  there are other simpler things you can do  like collapse all whitespace to a single space first   ps axu   grep   j boss    sed  s  s s    g    cut -d    -f5     That grep trick  by the way  is a neat way to only get the jboss processes and not the grep jboss one  ditto for the awk variant as well    The grep process will have a literal grep  j boss in its process command so will not be caught by the grep itself  which is looking for the character class  j  followed by boss   This is a nifty way to avoid the   grep xyz   grep -v grep paradigm that some people use

User · Answer

Shorter simpler solution  use cuts  cut on steroids I wrote   ps axu   grep   j boss    cuts 4   Note that cuts field indexes are zero-based so 5th field is specified as 4  http   arielf github io cuts   And even shorter  not using cut at all  is   pgrep jboss

User · Answer

If you want to pick columns from a ps output  any reason to not use -o   e g   ps ax -o pid vsz ps ax -o pid cmd   Minimum column width allocated  no padding  only single space field separator   ps ax --no-headers -o pid 1 vsz 1 cmd  3443 24600 -bash 8419 0  xfsalloc  8420 0  xfs mru cache  8602 489316  usr sbin apache2 -k start 12821 497240  usr sbin apache2 -k start 12824 497132  usr sbin apache2 -k start   Pid and vsz given 10 char width  1 space field separator   ps ax --no-headers -o pid 10 vsz 10 cmd    3443      24600 -bash   8419          0  xfsalloc    8420          0  xfs mru cache    8602     489316  usr sbin apache2 -k start  12821     497240  usr sbin apache2 -k start  12824     497132  usr sbin apache2 -k start   Used in a script -  oldpid 12824 echo  PID    oldpid   echo  Command    ps -ho cmd   oldpid

User · Answer

Personally  I tend to use awk for jobs like this   For example   ps axu  grep jboss   grep -v grep   awk   print  5

User · Answer

One way around this is to go    ps axu   grep jboss   sed  s  s     g    cut -d    -f3   to replace multiple consecutive spaces with a single one

User · Answer

awk version is probably the best way to go  but you can also use cut if you firstly squeeze the repeats with tr   ps axu   grep jbos s    tr -s       cut -d    -f5                                                                                                                                   get 5th field                                                       squeeze spaces                           avoid grep itself to appear in the list

User · Answer

As an alternative  there is always perl   ps aux   perl -lane  print  F 3     Or  if you want to get all fields starting at field  3  as stated in one of the answers above    ps aux   perl -lane  print  F 3    scalar  F

User · Answer

I still like the way Perl handles fields with white space  First field is  F 0      ps axu   grep dbus   perl -lane  print  F 4

User · Answer

I am going to nominate tr -s   blank   as the best answer   Why do we want to use cut  It has the magic command that says  we want the third field and every field after it  omitting the first two fields   cat log   tr -s   blank    cut -d    -f 3-    I do not believe there is an equivalent command for awk or perl split where we do not know how many fields there will be  ie out put the 3rd field through field X

User · Answer

Another way if you must use cut command  ps axu   grep  j boss  awk   1  1  cut -d    -f5   In Solaris  replace awk with nawk or  usr xpg4 bin awk

User · Answer

My approach is to store the PID to a file in  tmp  and to find the right process using  the -S option for ssh  That might be a misuse but works for me      bin bash  TARGET REDIS   1 -redis someserver com  PROXY  proxy somewhere com   LOCAL PORT   2 -6379   if     1      stop      then     kill  cat  tmp sshTunel  LOCAL PORT -pid      exit fi  set -x  ssh -f -i    ssh aws pem centos  PROXY -L  LOCAL PORT  TARGET REDIS 6379 -N -S  tmp sshTunel LOCAL PORT     AWS DocService dev  DNS alias   SSH PID       Only works with  amp  SSH PID  ps aux   grep sshTunel  LOCAL PORT    grep -v grep   awk   print  2    echo  SSH PID  gt   tmp sshTunel  LOCAL PORT -pid   Better approach might be to query for the SSH PID right before killing it  since the file might be stale and it would kill a wrong process

User · Answer

I like to use the tr -s command for this   ps aux   tr -s   blank     cut -d    -f3   This squeezes all white spaces down to 1 space   This way telling cut to use a space as a delimiter is honored as expected

[linux] How to specify more spaces for the delimiter using cut?

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