Bash script to run command when remote server is available
I have an application which depends on another remote service. What's I'd like to do is to make simple script which will run command locally when remote server will be available.
Something like this:
#!/bin/bash
CONNECTED = 0
while [ $CONNECTED != 1 ]; do
if [ $(ping my-service.com) != null ] then
my-command.sh
let CONNECTED = 1
fi
sleep 2
done
Actually it doesn't work because of ping command. It cause 'Name or service not known' error. I can compare string fully to make it work, but the question is if there are any ready-to-use commands, libs to do the same? Or mb this approach is bad and I should do it in another way.
bash
asked Nov 13 '18 at 14:20
Victor FedorenkoVictor Fedorenko
1218
add a comment |
I have an application which depends on another remote service. What's I'd like to do is to make simple script which will run command locally when remote server will be available.
Something like this:
#!/bin/bash
CONNECTED = 0
while [ $CONNECTED != 1 ]; do
if [ $(ping my-service.com) != null ] then
my-command.sh
let CONNECTED = 1
fi
sleep 2
done
Actually it doesn't work because of ping command. It cause 'Name or service not known' error. I can compare string fully to make it work, but the question is if there are any ready-to-use commands, libs to do the same? Or mb this approach is bad and I should do it in another way.
bash
asked Nov 13 '18 at 14:20
Victor FedorenkoVictor Fedorenko
1218
CONNECTED = 0there is no space when assigning a variable. It should beCONNECTED=0.[ $(ping my-service.com) != null ]is strange. Why would you expectpingprogram to print"null"string? Use smth likeif ping -c1 "$ip_addr" 2>/dev/null >/dev/nullto check if ip_addr is available. The errorName or service not knownindicates you have no internet connection from your machine at all or that your dns servers are not configured properly. Is this expected?
– Kamil Cuk
Nov 13 '18 at 14:26
add a comment |
I have an application which depends on another remote service. What's I'd like to do is to make simple script which will run command locally when remote server will be available.
Something like this:
#!/bin/bash
CONNECTED = 0
while [ $CONNECTED != 1 ]; do
if [ $(ping my-service.com) != null ] then
my-command.sh
let CONNECTED = 1
fi
sleep 2
done
Actually it doesn't work because of ping command. It cause 'Name or service not known' error. I can compare string fully to make it work, but the question is if there are any ready-to-use commands, libs to do the same? Or mb this approach is bad and I should do it in another way.
bash
asked Nov 13 '18 at 14:20
Victor FedorenkoVictor Fedorenko
1218
I have an application which depends on another remote service. What's I'd like to do is to make simple script which will run command locally when remote server will be available.
Something like this:
#!/bin/bash
CONNECTED = 0
while [ $CONNECTED != 1 ]; do
if [ $(ping my-service.com) != null ] then
my-command.sh
let CONNECTED = 1
fi
sleep 2
done
Actually it doesn't work because of ping command. It cause 'Name or service not known' error. I can compare string fully to make it work, but the question is if there are any ready-to-use commands, libs to do the same? Or mb this approach is bad and I should do it in another way.
bash
bash
asked Nov 13 '18 at 14:20
Victor FedorenkoVictor Fedorenko
1218
asked Nov 13 '18 at 14:20
Victor FedorenkoVictor Fedorenko
1218
asked Nov 13 '18 at 14:20
Victor FedorenkoVictor Fedorenko
1218
asked Nov 13 '18 at 14:20
Victor FedorenkoVictor Fedorenko
1218
asked Nov 13 '18 at 14:20
Victor FedorenkoVictor Fedorenko
1218
1218
CONNECTED = 0there is no space when assigning a variable. It should beCONNECTED=0.[ $(ping my-service.com) != null ]is strange. Why would you expectpingprogram to print"null"string? Use smth likeif ping -c1 "$ip_addr" 2>/dev/null >/dev/nullto check if ip_addr is available. The errorName or service not knownindicates you have no internet connection from your machine at all or that your dns servers are not configured properly. Is this expected?
– Kamil Cuk
Nov 13 '18 at 14:26
add a comment |
CONNECTED = 0there is no space when assigning a variable. It should beCONNECTED=0.[ $(ping my-service.com) != null ]is strange. Why would you expectpingprogram to print"null"string? Use smth likeif ping -c1 "$ip_addr" 2>/dev/null >/dev/nullto check if ip_addr is available. The errorName or service not knownindicates you have no internet connection from your machine at all or that your dns servers are not configured properly. Is this expected?
– Kamil Cuk
Nov 13 '18 at 14:26
CONNECTED = 0 there is no space when assigning a variable. It should be CONNECTED=0. [ $(ping my-service.com) != null ] is strange. Why would you expect ping program to print "null" string? Use smth like if ping -c1 "$ip_addr" 2>/dev/null >/dev/null to check if ip_addr is available. The error Name or service not known indicates you have no internet connection from your machine at all or that your dns servers are not configured properly. Is this expected?– Kamil Cuk
Nov 13 '18 at 14:26
CONNECTED = 0 there is no space when assigning a variable. It should be CONNECTED=0. [ $(ping my-service.com) != null ] is strange. Why would you expect ping program to print "null" string? Use smth like if ping -c1 "$ip_addr" 2>/dev/null >/dev/null to check if ip_addr is available. The error Name or service not known indicates you have no internet connection from your machine at all or that your dns servers are not configured properly. Is this expected?– Kamil Cuk
Nov 13 '18 at 14:26
add a comment |
1 Answer
1
active
oldest
votes
Try something like this:
#!/bin/bash
CONNECTED=1
while [[ $CONNECTED != 0 ]]; do
ping -c1 my-service.com
CONNECTED=$?
if [[ $CONNECTED == 0 ]] ; then
my-command.sh
fi
sleep 2
done
$? contains the return value of the last executed command (ping in this case). When ping return 0, it means no errors, so it will execute my-command.sh
answered Nov 13 '18 at 14:33
JoseLinaresJoseLinares
536312
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Try something like this:
#!/bin/bash
CONNECTED=1
while [[ $CONNECTED != 0 ]]; do
ping -c1 my-service.com
CONNECTED=$?
if [[ $CONNECTED == 0 ]] ; then
my-command.sh
fi
sleep 2
done
$? contains the return value of the last executed command (ping in this case). When ping return 0, it means no errors, so it will execute my-command.sh
answered Nov 13 '18 at 14:33
JoseLinaresJoseLinares
536312
add a comment |
Try something like this:
#!/bin/bash
CONNECTED=1
while [[ $CONNECTED != 0 ]]; do
ping -c1 my-service.com
CONNECTED=$?
if [[ $CONNECTED == 0 ]] ; then
my-command.sh
fi
sleep 2
done
$? contains the return value of the last executed command (ping in this case). When ping return 0, it means no errors, so it will execute my-command.sh
answered Nov 13 '18 at 14:33
JoseLinaresJoseLinares
536312
add a comment |
Try something like this:
#!/bin/bash
CONNECTED=1
while [[ $CONNECTED != 0 ]]; do
ping -c1 my-service.com
CONNECTED=$?
if [[ $CONNECTED == 0 ]] ; then
my-command.sh
fi
sleep 2
done
$? contains the return value of the last executed command (ping in this case). When ping return 0, it means no errors, so it will execute my-command.sh
answered Nov 13 '18 at 14:33
JoseLinaresJoseLinares
536312
Try something like this:
#!/bin/bash
CONNECTED=1
while [[ $CONNECTED != 0 ]]; do
ping -c1 my-service.com
CONNECTED=$?
if [[ $CONNECTED == 0 ]] ; then
my-command.sh
fi
sleep 2
done
$? contains the return value of the last executed command (ping in this case). When ping return 0, it means no errors, so it will execute my-command.sh
answered Nov 13 '18 at 14:33
JoseLinaresJoseLinares
536312
answered Nov 13 '18 at 14:33
JoseLinaresJoseLinares
536312
answered Nov 13 '18 at 14:33
JoseLinaresJoseLinares
536312
answered Nov 13 '18 at 14:33
JoseLinaresJoseLinares
536312
536312
add a comment |
add a comment |
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CONNECTED = 0there is no space when assigning a variable. It should beCONNECTED=0.[ $(ping my-service.com) != null ]is strange. Why would you expectpingprogram to print"null"string? Use smth likeif ping -c1 "$ip_addr" 2>/dev/null >/dev/nullto check if ip_addr is available. The errorName or service not knownindicates you have no internet connection from your machine at all or that your dns servers are not configured properly. Is this expected?– Kamil Cuk
Nov 13 '18 at 14:26