Nmap not working when implemented in crontab
I am trying to scan the network every day at a particular time(below example at 12:18) by using cronjobs and then output the IPs in a file. The command works perfectly but does not work if implemented in cronjobs. The following is implemented in /etc/crontab:
18 12 * * * root /usr/bin/nmap -O 10.0.0.10-253 | grep 'Nmap scan' |
cut -d' ' -f5> HostList
linux networking bash cron nmap
asked Feb 15 at 11:30
Lgrech25Lgrech25
61
add a comment |
I am trying to scan the network every day at a particular time(below example at 12:18) by using cronjobs and then output the IPs in a file. The command works perfectly but does not work if implemented in cronjobs. The following is implemented in /etc/crontab:
18 12 * * * root /usr/bin/nmap -O 10.0.0.10-253 | grep 'Nmap scan' |
cut -d' ' -f5> HostList
linux networking bash cron nmap
asked Feb 15 at 11:30
Lgrech25Lgrech25
61
add a comment |
I am trying to scan the network every day at a particular time(below example at 12:18) by using cronjobs and then output the IPs in a file. The command works perfectly but does not work if implemented in cronjobs. The following is implemented in /etc/crontab:
18 12 * * * root /usr/bin/nmap -O 10.0.0.10-253 | grep 'Nmap scan' |
cut -d' ' -f5> HostList
linux networking bash cron nmap
asked Feb 15 at 11:30
Lgrech25Lgrech25
61
I am trying to scan the network every day at a particular time(below example at 12:18) by using cronjobs and then output the IPs in a file. The command works perfectly but does not work if implemented in cronjobs. The following is implemented in /etc/crontab:
18 12 * * * root /usr/bin/nmap -O 10.0.0.10-253 | grep 'Nmap scan' |
cut -d' ' -f5> HostList
linux networking bash cron nmap
linux networking bash cron nmap
asked Feb 15 at 11:30
Lgrech25Lgrech25
61
asked Feb 15 at 11:30
Lgrech25Lgrech25
61
asked Feb 15 at 11:30
Lgrech25Lgrech25
61
asked Feb 15 at 11:30
Lgrech25Lgrech25
61
asked Feb 15 at 11:30
Lgrech25Lgrech25
61
61
add a comment |
add a comment |
1 Answer
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The most likely answer when a functional manual command doesn't behave properly when run as a cron job is because something is different when you run the command manually versus when cron spawns the job. That difference is most commonly that the PATH isn't the same, or the PWD (current directory) isn't the same.
Solve those problems by specifying absolute paths on executables and filenames:
18 12 * * * root /usr/bin/nmap -O 10.0.0.10-253 | /bin/grep 'Nmap scan' | /usr/bin/cut -d' ' -f5 > /var/tmp/HostList
Those paths are untested examples, chosen for illustrative purposes. You will need to verify the location of the executables and the desired location of your output file, and adjust the crontab entry accordingly.
answered Feb 15 at 23:10
Jim L.Jim L.
42117
add a comment |
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1 Answer
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1 Answer
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active
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The most likely answer when a functional manual command doesn't behave properly when run as a cron job is because something is different when you run the command manually versus when cron spawns the job. That difference is most commonly that the PATH isn't the same, or the PWD (current directory) isn't the same.
Solve those problems by specifying absolute paths on executables and filenames:
18 12 * * * root /usr/bin/nmap -O 10.0.0.10-253 | /bin/grep 'Nmap scan' | /usr/bin/cut -d' ' -f5 > /var/tmp/HostList
Those paths are untested examples, chosen for illustrative purposes. You will need to verify the location of the executables and the desired location of your output file, and adjust the crontab entry accordingly.
answered Feb 15 at 23:10
Jim L.Jim L.
42117
add a comment |
The most likely answer when a functional manual command doesn't behave properly when run as a cron job is because something is different when you run the command manually versus when cron spawns the job. That difference is most commonly that the PATH isn't the same, or the PWD (current directory) isn't the same.
Solve those problems by specifying absolute paths on executables and filenames:
18 12 * * * root /usr/bin/nmap -O 10.0.0.10-253 | /bin/grep 'Nmap scan' | /usr/bin/cut -d' ' -f5 > /var/tmp/HostList
Those paths are untested examples, chosen for illustrative purposes. You will need to verify the location of the executables and the desired location of your output file, and adjust the crontab entry accordingly.
answered Feb 15 at 23:10
Jim L.Jim L.
42117
add a comment |
The most likely answer when a functional manual command doesn't behave properly when run as a cron job is because something is different when you run the command manually versus when cron spawns the job. That difference is most commonly that the PATH isn't the same, or the PWD (current directory) isn't the same.
Solve those problems by specifying absolute paths on executables and filenames:
18 12 * * * root /usr/bin/nmap -O 10.0.0.10-253 | /bin/grep 'Nmap scan' | /usr/bin/cut -d' ' -f5 > /var/tmp/HostList
Those paths are untested examples, chosen for illustrative purposes. You will need to verify the location of the executables and the desired location of your output file, and adjust the crontab entry accordingly.
answered Feb 15 at 23:10
Jim L.Jim L.
42117
The most likely answer when a functional manual command doesn't behave properly when run as a cron job is because something is different when you run the command manually versus when cron spawns the job. That difference is most commonly that the PATH isn't the same, or the PWD (current directory) isn't the same.
Solve those problems by specifying absolute paths on executables and filenames:
18 12 * * * root /usr/bin/nmap -O 10.0.0.10-253 | /bin/grep 'Nmap scan' | /usr/bin/cut -d' ' -f5 > /var/tmp/HostList
Those paths are untested examples, chosen for illustrative purposes. You will need to verify the location of the executables and the desired location of your output file, and adjust the crontab entry accordingly.
answered Feb 15 at 23:10
Jim L.Jim L.
42117
edited Feb 18 at 21:34
answered Feb 15 at 23:10
Jim L.Jim L.
42117
answered Feb 15 at 23:10
Jim L.Jim L.
42117
answered Feb 15 at 23:10
Jim L.Jim L.
42117
42117
add a comment |
add a comment |
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