Run a string as a command within a Bash script

Question

I have a Bash script that builds a string to run as a command  Script       bin bash  matchdir   home joao robocup runner workdir matches testmatch    teamAComm   pwd  a sh  teamBComm   pwd  b sh  include   pwd  server official conf  serverbin   usr local bin rcssserver   cd  matchdir illcommando   serverbin include   include  server  team l start      teamAComm   server  team r start      teamBComm   CSVSaver  save  true  CSVSaver  filename    out csv    echo  running   illcommando     illcommando  gt  server-output log 2 gt  server-error log  illcommando   which does not seem to supply the arguments correctly to the  serverbin   Script output   running   usr local bin rcssserver include   home joao robocup runner workdir server official conf  server  team l start     home joao robocup runner workdir a sh  server  team r start     home joao robocup runner workdir b sh  CSVSaver  save  true  CSVSaver  filename    out csv  rcssserver-14 0 1  Copyright  C  1995  1996  1997  1998  1999 Electrotechnical Laboratory  2000 - 2009 RoboCup Soccer Simulator Maintenance Group    Usage   usr local bin rcssserver   - -  namespace  option value                                     - -   namespace   help                                     - -  include file  Options      help         display generic help      include file         parse the specified configuration file   Configuration files         have the same format as the command line options  The         configuration file specified will be parsed before all         subsequent options       server  help         display detailed help for the  server  module      player  help         display detailed help for the  player  module      CSVSaver  help         display detailed help for the  CSVSaver  module  CSVSaver Options      CSVSaver  save  lt on off true false 1 0  gt          If save is on true  then the saver will attempt to save the         results to the database   Otherwise it will do nothing           current value  false      CSVSaver  filename   lt STRING gt           The file to save the results to   If this file does not         exist it will be created   If the file does exist  the results         will be appended to the end           current value   out csv    if I just paste the command  usr local bin rcssserver include   home joao robocup runner workdir server official conf  server  team l start     home joao robocup runner workdir a sh  server  team r start     home joao robocup runner workdir b sh  CSVSaver  save  true  CSVSaver  filename    out csv   in the output after  runnning     it works fine

User · Answer

For me echo XYZ 20200824 zip   grep -Eo     digit    4    digit    2    digit    2   was working fine but unable to store output of command into variable  I had same issue I tried eval but didn t got output  Here is answer for my problem  cmd   echo XYZ 20200824 zip   grep -Eo     digit    4    digit    2    digit    2    echo  cmd My output is now 20200824

User · Answer

I usually place commands in parentheses   commandStr   if that doesn t help I find bash debug mode great  run the script as bash -x script

User · Answer

don t put your commands in variables  just run it  matchdir   home joao robocup runner workdir matches testmatch   PWD   pwd  teamAComm   PWD a sh  teamBComm   PWD b sh  include   PWD server official conf  serverbin   usr local bin rcssserver      cd  matchdir  serverbin include  include server  team l start     teamAComm  server  team r start   teamBComm  CSVSaver  save  true  CSVSaver  filename    out csv

User · Answer

To see all commands that are being executed by the script  add the -x flag to your shabang line  and execute the command normally      bin bash -x  matchdir  quot  home joao robocup runner workdir matches testmatch  quot   teamAComm  quot  pwd  a sh quot  teamBComm  quot  pwd  b sh quot  include  quot  pwd  server official conf quot  serverbin   usr local bin rcssserver   cd  matchdir  serverbin include  quot  include quot  server  team l start  quot   teamAComm  quot  server  team r start  quot   teamBComm  quot  CSVSaver  save  true  CSVSaver  filename  out csv    Then if you sometimes want to ignore the debug output  redirect stderr somewhere

User · Answer

Here is my gradle build script that executes strings stored in heredocs   current directory    realpath       GENERATED   current directory   GENERATED  build gradle    realpath build gradle       touch because  gitignore ignores this folder  touch  GENERATED  COPY BUILD FILE    cat  lt  lt COPY BUILD FILE HEREDOC      cp           build gradle           GENERATED build gradle  COPY BUILD FILE HEREDOC    COPY BUILD FILE  GRADLE COMMAND    cat  lt  lt GRADLE COMMAND HEREDOC      gradle run          --build-file                     GENERATED build gradle          --gradle-user-home               GENERATED            --no-daemon  GRADLE COMMAND HEREDOC    GRADLE COMMAND   The lone     are kind of ugly  But I have no clue how to fix that asthetic aspect

User · Answer

your command string       output   eval   your command string   echo   output

User · Answer

You can use eval to execute a string   eval  illcommando

User · Answer

me casts raise dead    I was looking for something like this  but I also needed to reuse the same string minus two parameters so I ended up with something like   my exe          mysql -sN -e  select  1 from heat stack where heat stack name    2         This is something I use to monitor openstack heat stack creation  In this case I expect two conditions  an action  CREATE  and a status  COMPLETE  on a stack named  Somestack   To get those variables I can do something like   ACTION   my exe action Somestack  STATUS   my exe status Somestack  if      ACTION      CREATE      amp  amp       STATUS      COMPLETE

[bash] Run a string as a command within a Bash script

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