Running bash inside cronjob












1















I have this cronjob to run every minute



*/1 * * * * root sh /test.sh


My /test.sh logs the result of "top" and "free" command. It works fine when I run it manually on terminal with "sh /teste.sh" and saves the output to a nice file, however when the cron job runs it only saves the result of the command "free" below. Check this please:



printf "n" >> "log_lojar_top_free.txt"

printf %s "$(date)" >> "log_lojar_top_free.txt"

printf 't' >> "log_lojar_top_free.txt"

top -b -n 3 -d 1 | grep "Cpu" |  tail -n 1 | awk '/^%Cpu(s)/ {printf $2}' >> "log_lojar_top_free.txt"

printf 't' >> "log_lojar_top_free.txt"

free | awk '/^Mem:/ {printf $7}' >> "log_lojar_top_free.txt"


What is the error that is causing that only the last line (free) to have it's output loged?






linux ubuntu centos







share|improve this question

























  • if you want to run a bash script then use bash, not sh. they're not the same thing. even if sh is a symlink to bash, bash behaves differently if called as sh rather than bash.

    – cas
    Oct 31 '15 at 0:51











  • you can do as cas suggests either by prefixing in crontab with /bin/bash instead of sh, or by starting your script with a shebang line: #!/bin/bash - see if it behaves better once you definitely have it running under bash and not some other shell. Another possibility is that you aren't looking in the right place for the output file. The cron job is running as root and since you didn't specify an output directory, only a file, it will probably save it at / - not a good place to use generally. Oh and BTW you don't need the /1.

    – gogoud
    Oct 31 '15 at 8:13













  • A quick check shows that my implementation of crond writes to the user's home directory. In my case, for root that's /root.

    – roaima
    Nov 3 '15 at 22:51
















1















I have this cronjob to run every minute



*/1 * * * * root sh /test.sh


My /test.sh logs the result of "top" and "free" command. It works fine when I run it manually on terminal with "sh /teste.sh" and saves the output to a nice file, however when the cron job runs it only saves the result of the command "free" below. Check this please:



printf "n" >> "log_lojar_top_free.txt"

printf %s "$(date)" >> "log_lojar_top_free.txt"

printf 't' >> "log_lojar_top_free.txt"

top -b -n 3 -d 1 | grep "Cpu" |  tail -n 1 | awk '/^%Cpu(s)/ {printf $2}' >> "log_lojar_top_free.txt"

printf 't' >> "log_lojar_top_free.txt"

free | awk '/^Mem:/ {printf $7}' >> "log_lojar_top_free.txt"


What is the error that is causing that only the last line (free) to have it's output loged?






linux ubuntu centos







share|improve this question

























  • if you want to run a bash script then use bash, not sh. they're not the same thing. even if sh is a symlink to bash, bash behaves differently if called as sh rather than bash.

    – cas
    Oct 31 '15 at 0:51











  • you can do as cas suggests either by prefixing in crontab with /bin/bash instead of sh, or by starting your script with a shebang line: #!/bin/bash - see if it behaves better once you definitely have it running under bash and not some other shell. Another possibility is that you aren't looking in the right place for the output file. The cron job is running as root and since you didn't specify an output directory, only a file, it will probably save it at / - not a good place to use generally. Oh and BTW you don't need the /1.

    – gogoud
    Oct 31 '15 at 8:13













  • A quick check shows that my implementation of crond writes to the user's home directory. In my case, for root that's /root.

    – roaima
    Nov 3 '15 at 22:51














1












1








1








I have this cronjob to run every minute



*/1 * * * * root sh /test.sh


My /test.sh logs the result of "top" and "free" command. It works fine when I run it manually on terminal with "sh /teste.sh" and saves the output to a nice file, however when the cron job runs it only saves the result of the command "free" below. Check this please:



printf "n" >> "log_lojar_top_free.txt"

printf %s "$(date)" >> "log_lojar_top_free.txt"

printf 't' >> "log_lojar_top_free.txt"

top -b -n 3 -d 1 | grep "Cpu" |  tail -n 1 | awk '/^%Cpu(s)/ {printf $2}' >> "log_lojar_top_free.txt"

printf 't' >> "log_lojar_top_free.txt"

free | awk '/^Mem:/ {printf $7}' >> "log_lojar_top_free.txt"


What is the error that is causing that only the last line (free) to have it's output loged?






linux ubuntu centos







share|improve this question
















I have this cronjob to run every minute



*/1 * * * * root sh /test.sh


My /test.sh logs the result of "top" and "free" command. It works fine when I run it manually on terminal with "sh /teste.sh" and saves the output to a nice file, however when the cron job runs it only saves the result of the command "free" below. Check this please:



printf "n" >> "log_lojar_top_free.txt"

printf %s "$(date)" >> "log_lojar_top_free.txt"

printf 't' >> "log_lojar_top_free.txt"

top -b -n 3 -d 1 | grep "Cpu" |  tail -n 1 | awk '/^%Cpu(s)/ {printf $2}' >> "log_lojar_top_free.txt"

printf 't' >> "log_lojar_top_free.txt"

free | awk '/^Mem:/ {printf $7}' >> "log_lojar_top_free.txt"


What is the error that is causing that only the last line (free) to have it's output loged?






linux ubuntu centos




linux ubuntu centos






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited 2 hours ago









Guillermo Mosse

1033




1033










asked Oct 30 '15 at 22:46









SamulSamul

18117




18117













  • if you want to run a bash script then use bash, not sh. they're not the same thing. even if sh is a symlink to bash, bash behaves differently if called as sh rather than bash.

    – cas
    Oct 31 '15 at 0:51











  • you can do as cas suggests either by prefixing in crontab with /bin/bash instead of sh, or by starting your script with a shebang line: #!/bin/bash - see if it behaves better once you definitely have it running under bash and not some other shell. Another possibility is that you aren't looking in the right place for the output file. The cron job is running as root and since you didn't specify an output directory, only a file, it will probably save it at / - not a good place to use generally. Oh and BTW you don't need the /1.

    – gogoud
    Oct 31 '15 at 8:13













  • A quick check shows that my implementation of crond writes to the user's home directory. In my case, for root that's /root.

    – roaima
    Nov 3 '15 at 22:51



















  • if you want to run a bash script then use bash, not sh. they're not the same thing. even if sh is a symlink to bash, bash behaves differently if called as sh rather than bash.

    – cas
    Oct 31 '15 at 0:51











  • you can do as cas suggests either by prefixing in crontab with /bin/bash instead of sh, or by starting your script with a shebang line: #!/bin/bash - see if it behaves better once you definitely have it running under bash and not some other shell. Another possibility is that you aren't looking in the right place for the output file. The cron job is running as root and since you didn't specify an output directory, only a file, it will probably save it at / - not a good place to use generally. Oh and BTW you don't need the /1.

    – gogoud
    Oct 31 '15 at 8:13













  • A quick check shows that my implementation of crond writes to the user's home directory. In my case, for root that's /root.

    – roaima
    Nov 3 '15 at 22:51

















if you want to run a bash script then use bash, not sh. they're not the same thing. even if sh is a symlink to bash, bash behaves differently if called as sh rather than bash.

– cas
Oct 31 '15 at 0:51





if you want to run a bash script then use bash, not sh. they're not the same thing. even if sh is a symlink to bash, bash behaves differently if called as sh rather than bash.

– cas
Oct 31 '15 at 0:51













you can do as cas suggests either by prefixing in crontab with /bin/bash instead of sh, or by starting your script with a shebang line: #!/bin/bash - see if it behaves better once you definitely have it running under bash and not some other shell. Another possibility is that you aren't looking in the right place for the output file. The cron job is running as root and since you didn't specify an output directory, only a file, it will probably save it at / - not a good place to use generally. Oh and BTW you don't need the /1.

– gogoud
Oct 31 '15 at 8:13







you can do as cas suggests either by prefixing in crontab with /bin/bash instead of sh, or by starting your script with a shebang line: #!/bin/bash - see if it behaves better once you definitely have it running under bash and not some other shell. Another possibility is that you aren't looking in the right place for the output file. The cron job is running as root and since you didn't specify an output directory, only a file, it will probably save it at / - not a good place to use generally. Oh and BTW you don't need the /1.

– gogoud
Oct 31 '15 at 8:13















A quick check shows that my implementation of crond writes to the user's home directory. In my case, for root that's /root.

– roaima
Nov 3 '15 at 22:51





A quick check shows that my implementation of crond writes to the user's home directory. In my case, for root that's /root.

– roaima
Nov 3 '15 at 22:51










2 Answers
2






active

oldest

votes


















1














As suggested by others, try to direct use the bash shebang in your script or prefix by using bash instead of sh. For I don't know what system you're actually running, I recently ran into trouble calling a script usign /bin/sh -c myscript.sh under ubuntu which is a debian derivate which uses dash instead of bash.



Maybe this is the key to your problem.



EDIT: I've got it working with this crontab entry, done as root with crontab -e:



*/1 * * * * /bin/bash -c "/test.sh"





share|improve this answer


























  • Good catch re dash. However, the OP's script appears to run equivalently under bash, sh (for some value of sh) and dash.

    – roaima
    Nov 3 '15 at 23:22



















0














This version works for me. However, as your own script also works here I'm not entirely sure this will fix your problem.



System-wide crontab entry (omit the root field if this is root's own crontab, as accessed with crontab -e):



* * * * * root /root/test.sh


As far as I can detemine, your script takes the third iteration from top and collects the CPU usermode percentage. It also collects the cached memory value from free. Here I've dispensed with free and extracted the same value from the third iteration of top. Copy this script to /root/test.sh (and make it executable):



#!/bin/bash

top -b -n 3 -d 1 |

    awk -v date="$(date)" '

        /^%Cpu/ {cpu=$2}

        /cached Mem/ {cached=$9}

        END {printf "n%st%st%s", date, cpu, cached}

    ' >> /root/log_lojar_top_free.txt


Make the script executable:



chmod +x /root/test.sh





share|improve this answer























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    2 Answers
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    2 Answers
    2






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    1














    As suggested by others, try to direct use the bash shebang in your script or prefix by using bash instead of sh. For I don't know what system you're actually running, I recently ran into trouble calling a script usign /bin/sh -c myscript.sh under ubuntu which is a debian derivate which uses dash instead of bash.



    Maybe this is the key to your problem.



    EDIT: I've got it working with this crontab entry, done as root with crontab -e:



    */1 * * * * /bin/bash -c "/test.sh"





    share|improve this answer


























    • Good catch re dash. However, the OP's script appears to run equivalently under bash, sh (for some value of sh) and dash.

      – roaima
      Nov 3 '15 at 23:22
















    1














    As suggested by others, try to direct use the bash shebang in your script or prefix by using bash instead of sh. For I don't know what system you're actually running, I recently ran into trouble calling a script usign /bin/sh -c myscript.sh under ubuntu which is a debian derivate which uses dash instead of bash.



    Maybe this is the key to your problem.



    EDIT: I've got it working with this crontab entry, done as root with crontab -e:



    */1 * * * * /bin/bash -c "/test.sh"





    share|improve this answer


























    • Good catch re dash. However, the OP's script appears to run equivalently under bash, sh (for some value of sh) and dash.

      – roaima
      Nov 3 '15 at 23:22














    1












    1








    1







    As suggested by others, try to direct use the bash shebang in your script or prefix by using bash instead of sh. For I don't know what system you're actually running, I recently ran into trouble calling a script usign /bin/sh -c myscript.sh under ubuntu which is a debian derivate which uses dash instead of bash.



    Maybe this is the key to your problem.



    EDIT: I've got it working with this crontab entry, done as root with crontab -e:



    */1 * * * * /bin/bash -c "/test.sh"





    share|improve this answer















    As suggested by others, try to direct use the bash shebang in your script or prefix by using bash instead of sh. For I don't know what system you're actually running, I recently ran into trouble calling a script usign /bin/sh -c myscript.sh under ubuntu which is a debian derivate which uses dash instead of bash.



    Maybe this is the key to your problem.



    EDIT: I've got it working with this crontab entry, done as root with crontab -e:



    */1 * * * * /bin/bash -c "/test.sh"






    share|improve this answer














    share|improve this answer



    share|improve this answer








    edited Nov 3 '15 at 23:41

























    answered Nov 3 '15 at 23:19









    ferdyferdy

    1496




    1496













    • Good catch re dash. However, the OP's script appears to run equivalently under bash, sh (for some value of sh) and dash.

      – roaima
      Nov 3 '15 at 23:22



















    • Good catch re dash. However, the OP's script appears to run equivalently under bash, sh (for some value of sh) and dash.

      – roaima
      Nov 3 '15 at 23:22

















    Good catch re dash. However, the OP's script appears to run equivalently under bash, sh (for some value of sh) and dash.

    – roaima
    Nov 3 '15 at 23:22





    Good catch re dash. However, the OP's script appears to run equivalently under bash, sh (for some value of sh) and dash.

    – roaima
    Nov 3 '15 at 23:22













    0














    This version works for me. However, as your own script also works here I'm not entirely sure this will fix your problem.



    System-wide crontab entry (omit the root field if this is root's own crontab, as accessed with crontab -e):



    * * * * * root /root/test.sh


    As far as I can detemine, your script takes the third iteration from top and collects the CPU usermode percentage. It also collects the cached memory value from free. Here I've dispensed with free and extracted the same value from the third iteration of top. Copy this script to /root/test.sh (and make it executable):



    #!/bin/bash
    
top -b -n 3 -d 1 |
    
    awk -v date="$(date)" '
    
        /^%Cpu/ {cpu=$2}
    
        /cached Mem/ {cached=$9}
    
        END {printf "n%st%st%s", date, cpu, cached}
    
    ' >> /root/log_lojar_top_free.txt


    Make the script executable:



    chmod +x /root/test.sh





    share|improve this answer




























      0














      This version works for me. However, as your own script also works here I'm not entirely sure this will fix your problem.



      System-wide crontab entry (omit the root field if this is root's own crontab, as accessed with crontab -e):



      * * * * * root /root/test.sh


      As far as I can detemine, your script takes the third iteration from top and collects the CPU usermode percentage. It also collects the cached memory value from free. Here I've dispensed with free and extracted the same value from the third iteration of top. Copy this script to /root/test.sh (and make it executable):



      #!/bin/bash
      
top -b -n 3 -d 1 |
      
    awk -v date="$(date)" '
      
        /^%Cpu/ {cpu=$2}
      
        /cached Mem/ {cached=$9}
      
        END {printf "n%st%st%s", date, cpu, cached}
      
    ' >> /root/log_lojar_top_free.txt


      Make the script executable:



      chmod +x /root/test.sh





      share|improve this answer


























        0












        0








        0







        This version works for me. However, as your own script also works here I'm not entirely sure this will fix your problem.



        System-wide crontab entry (omit the root field if this is root's own crontab, as accessed with crontab -e):



        * * * * * root /root/test.sh


        As far as I can detemine, your script takes the third iteration from top and collects the CPU usermode percentage. It also collects the cached memory value from free. Here I've dispensed with free and extracted the same value from the third iteration of top. Copy this script to /root/test.sh (and make it executable):



        #!/bin/bash
        
top -b -n 3 -d 1 |
        
    awk -v date="$(date)" '
        
        /^%Cpu/ {cpu=$2}
        
        /cached Mem/ {cached=$9}
        
        END {printf "n%st%st%s", date, cpu, cached}
        
    ' >> /root/log_lojar_top_free.txt


        Make the script executable:



        chmod +x /root/test.sh





        share|improve this answer













        This version works for me. However, as your own script also works here I'm not entirely sure this will fix your problem.



        System-wide crontab entry (omit the root field if this is root's own crontab, as accessed with crontab -e):



        * * * * * root /root/test.sh


        As far as I can detemine, your script takes the third iteration from top and collects the CPU usermode percentage. It also collects the cached memory value from free. Here I've dispensed with free and extracted the same value from the third iteration of top. Copy this script to /root/test.sh (and make it executable):



        #!/bin/bash
        
top -b -n 3 -d 1 |
        
    awk -v date="$(date)" '
        
        /^%Cpu/ {cpu=$2}
        
        /cached Mem/ {cached=$9}
        
        END {printf "n%st%st%s", date, cpu, cached}
        
    ' >> /root/log_lojar_top_free.txt


        Make the script executable:



        chmod +x /root/test.sh






        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 3 '15 at 23:11









        roaimaroaima

        45.4k757123




        45.4k757123






























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