Running awk command in remote host fails

Question

I am running a shell script to run awk command on a remote host. The awk command runs fine locally, but when run for the remote host fails (the redirected file is empty):

Here is the script run on remote host:

host=160.110.235.30
IFM_MOUNT=/opt/insiteone/fuse-mount1
ssh -T root@$host << 'EOF'
awk -v p="$IFM_MOUNT" '{a[NR]=$0}{if(match($0,p)>0){for(i=NR-2;i<=NR+7;i++)d[i]=1}}END{for(i=1;i<=NR;i++)if(!d[i])print a[i]} ' smb.conf >> smb.conf.tmp
EOF

smb.conf.tmp is empty in remote host !!

Locally:

cat smb.conf
[DCCAArchive]
        comment = DCCA Archive File System
        path = /opt/insiteone/fuse-mount/ifm
        read only = No
        case sensitive = yes
        public = yes
        case sensitive = yes
        writeable = yes
        create mask=0777
        guest ok = Yes


[DCCAArchive1]
        comment = DCCA Archive File System
        path = /opt/insiteone/fuse-mount1/ifm
        read only = No
        case sensitive = yes
        public = yes
        case sensitive = yes
        writeable = yes
        create mask=0777
        guest ok = Yes

Running awk locally from shell:
IFM_MOUNT=/opt/insiteone/fuse-mount1
awk -v p="$IFM_MOUNT" '{a[NR]=$0}{if(match($0,p)>0){for(i=NR-2;i<=NR+7;i++)d[i]=1}}END{for(i=1;i<=NR;i++)if(!d[i])print a[i]} ' smb.conf >> smb.conf.tmp

Output (deletes the line matching IFM_MOUNT):
[DCCAArchive]
        comment = DCCA Archive File System
        path = /opt/insiteone/fuse-mount/ifm
        read only = No
        case sensitive = yes
        public = yes
        case sensitive = yes
        writeable = yes
        create mask=0777
        guest ok = Yes

I followed this link for awk running on remote host

Answer 1

The quoting mechanism you have chosen prevents the remote shell from seeing the locally defined variable IFM_MOUNT. Use double quotes instead to have the value interpolated into the string.

host=160.110.235.30
IFM_MOUNT=/opt/insiteone/fuse-mount1
ssh root@$host "awk -v p='$IFM_MOUNT' '
    {a[NR]=\$0}
    {if(match(\$0,p)>0)
      for(i=NR-2;i<=NR+7;i++)
          d[i]=1}
    END{
      for(i=1;i<=NR;i++)if(!d[i])print a[i]} ' smb.conf >> smb.conf.tmp"

Notice how single quotes inside double quotes do not actually quote anything; and so any literal dollar sign needs to be escaped with a backslash.

(I was tempted to make a more substantial refactoring of your Awk script, but that would perhaps obscure the point.)