Check if program is running with bash shell script

Question

This is an example of a bash script which checks for some running process  daemon or service  and does specific actions  reload  sends mail  if there is no such process running   check process              check the args         if     1                  then                 return 0         fi           PROCESS NUM   gt  get the process number regarding the given thread name         PROCESS NUM  ps -ef   grep   1    grep -v  grep    wc -l            for degbuging             PROCESS NUM         if    PROCESS NUM -eq 1            then                 return 1         else                 return 0         fi      Check whether the instance of thread exists  while   1     do         echo  begin checking             check process  python test demo py    the thread name         CHECK RET              if    CHECK RET -eq 0      none exist         then                   do something            fi         sleep 60 done   However  it doesn t work  I got  ERROR  Garbage option   for the ps command  What s wrong with these scripts  Thanks

User · Answer

PROCESS  process name shown in ps -ef  START OR STOP 1          0   start   1   stop  MAX 30 COUNT 0  until    COUNT -gt  MAX     do         echo -ne             PROCESS NUM   ps -ef   grep   PROCESS    grep -v  basename  0    grep -v  grep    wc -l          if    PROCESS NUM -gt 0    then              runs             RET 1         else              stopped             RET 0         fi          if    RET -eq  START OR STOP    then             sleep 5  wait            else             if    START OR STOP -eq 1    then                     echo -ne   stopped              else                     echo -ne   started              fi             echo             exit 0         fi         let COUNT COUNT 1 done  if    START OR STOP -eq 1    then     echo -ne      PROCESS failed to stop     else     echo -ne      PROCESS failed to start     fi echo exit 1

User · Answer

You can achieve almost everything in PROCESS NUM with this one-liner      pgrep  1     amp  amp  return 1    return 0   if you re looking for a partial match  i e  program is named foobar and you want your  1 to be just foo you can add the -f switch to pgrep       pgrep -f  1      amp  amp  return 1    return 0   Putting it all together your script could be reworked like this      bin bash  check process       echo   ts  checking  1        1           amp  amp  return 0      pgrep -n  1     amp  amp  return 1    return 0    while   1    do      timestamp   ts  date   T     echo   ts  begin checking       check process  dropbox         -eq 0    amp  amp  echo   ts  not running  restarting      amp  amp   dropbox start -i  gt   dev null    sleep 5 done   Running it would look like this     SHELL  1 22 07 26  begin checking    22 07 26  checking dropbox 22 07 31  begin checking    22 07 31  checking dropbox    SHELL  2   dropbox stop Dropbox daemon stopped     SHELL  1 22 07 36  begin checking    22 07 36  checking dropbox 22 07 36  not running  restarting    22 07 42  begin checking    22 07 42  checking dropbox   Hope this helps

User · Answer

If you want to execute that command  you should probably change   PROCESS NUM  ps -ef   grep   1    grep -v  grep    wc -l    to   PROCESS NUM   ps -ef   grep   1    grep -v  grep    wc -l

[shell] Check if program is running with bash shell script?

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