How to trigger a command after named pipe closes?
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2
How can I execute some command after the named pipe has been readout in other end. I was trying to use trap. But nothing happens. My script is something like below.
#!/bin/sh
cleanup()
echo "Caught Signal ... cleaning up the background process."
trap cleanup PIPE
if [ ! -p "/tmp/mysqld.init" ]; then
mkfifo /tmp/mysqld.init
fi
echo "CREATE DATABASE IF NOT EXISTS test;" > /tmp/mysqld.init &
exec mysqld --init-file="/tmp/mysqld.init"
Note: This is my docker image's entrypoint script and exec is necessary in my case.
shell-script background-process signals fifo trap
asked Jan 20 at 0:12
SkyRarSkyRar
199
add a comment |
2
How can I execute some command after the named pipe has been readout in other end. I was trying to use trap. But nothing happens. My script is something like below.
#!/bin/sh
cleanup()
echo "Caught Signal ... cleaning up the background process."
trap cleanup PIPE
if [ ! -p "/tmp/mysqld.init" ]; then
mkfifo /tmp/mysqld.init
fi
echo "CREATE DATABASE IF NOT EXISTS test;" > /tmp/mysqld.init &
exec mysqld --init-file="/tmp/mysqld.init"
Note: This is my docker image's entrypoint script and exec is necessary in my case.
shell-script background-process signals fifo trap
asked Jan 20 at 0:12
SkyRarSkyRar
199
If the exec is successful, the shell will no longer exist, so there's no way for the shell to write to a closed pipe and no way the trap body would run. What do you want to do after the pipe has been read?
– Mark Plotnick
Jan 20 at 15:56
I am not sure what do you mean by shell will no longer exist. But in my case as I am creating a docker imagemysqldruns as pid 1 for ever. I just want to close the child/background process after the pipe has been read.
– SkyRar
Jan 20 at 16:59
add a comment |
2
2
2
2
How can I execute some command after the named pipe has been readout in other end. I was trying to use trap. But nothing happens. My script is something like below.
#!/bin/sh
cleanup()
echo "Caught Signal ... cleaning up the background process."
trap cleanup PIPE
if [ ! -p "/tmp/mysqld.init" ]; then
mkfifo /tmp/mysqld.init
fi
echo "CREATE DATABASE IF NOT EXISTS test;" > /tmp/mysqld.init &
exec mysqld --init-file="/tmp/mysqld.init"
Note: This is my docker image's entrypoint script and exec is necessary in my case.
shell-script background-process signals fifo trap
asked Jan 20 at 0:12
SkyRarSkyRar
199
How can I execute some command after the named pipe has been readout in other end. I was trying to use trap. But nothing happens. My script is something like below.
#!/bin/sh
cleanup()
echo "Caught Signal ... cleaning up the background process."
trap cleanup PIPE
if [ ! -p "/tmp/mysqld.init" ]; then
mkfifo /tmp/mysqld.init
fi
echo "CREATE DATABASE IF NOT EXISTS test;" > /tmp/mysqld.init &
exec mysqld --init-file="/tmp/mysqld.init"
Note: This is my docker image's entrypoint script and exec is necessary in my case.
shell-script background-process signals fifo trap
shell-script background-process signals fifo trap
asked Jan 20 at 0:12
SkyRarSkyRar
199
asked Jan 20 at 0:12
SkyRarSkyRar
199
asked Jan 20 at 0:12
SkyRarSkyRar
199
asked Jan 20 at 0:12
SkyRarSkyRar
199
asked Jan 20 at 0:12
SkyRarSkyRar
199
199
If the exec is successful, the shell will no longer exist, so there's no way for the shell to write to a closed pipe and no way the trap body would run. What do you want to do after the pipe has been read?
– Mark Plotnick
Jan 20 at 15:56
I am not sure what do you mean by shell will no longer exist. But in my case as I am creating a docker imagemysqldruns as pid 1 for ever. I just want to close the child/background process after the pipe has been read.
– SkyRar
Jan 20 at 16:59
add a comment |
If the exec is successful, the shell will no longer exist, so there's no way for the shell to write to a closed pipe and no way the trap body would run. What do you want to do after the pipe has been read?
– Mark Plotnick
Jan 20 at 15:56
I am not sure what do you mean by shell will no longer exist. But in my case as I am creating a docker imagemysqldruns as pid 1 for ever. I just want to close the child/background process after the pipe has been read.
– SkyRar
Jan 20 at 16:59
If the exec is successful, the shell will no longer exist, so there's no way for the shell to write to a closed pipe and no way the trap body would run. What do you want to do after the pipe has been read?
– Mark Plotnick
Jan 20 at 15:56
If the exec is successful, the shell will no longer exist, so there's no way for the shell to write to a closed pipe and no way the trap body would run. What do you want to do after the pipe has been read?
– Mark Plotnick
Jan 20 at 15:56
I am not sure what do you mean by shell will no longer exist. But in my case as I am creating a docker image
mysqld runs as pid 1 for ever. I just want to close the child/background process after the pipe has been read.– SkyRar
Jan 20 at 16:59
I am not sure what do you mean by shell will no longer exist. But in my case as I am creating a docker image
mysqld runs as pid 1 for ever. I just want to close the child/background process after the pipe has been read.– SkyRar
Jan 20 at 16:59
add a comment |
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If the exec is successful, the shell will no longer exist, so there's no way for the shell to write to a closed pipe and no way the trap body would run. What do you want to do after the pipe has been read?
– Mark Plotnick
Jan 20 at 15:56
I am not sure what do you mean by shell will no longer exist. But in my case as I am creating a docker image
mysqldruns as pid 1 for ever. I just want to close the child/background process after the pipe has been read.– SkyRar
Jan 20 at 16:59