File Status Map (sendmail)

Abstract

The document describes how to add file status map to sendmail.

The map can chek presence of file or directory and report files size. It can be used for rela time checks if given cyrus mailbox exists.

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Usage

After you compile in support for fstat map define fstat map in you sendmail.mc:

Pass test name in key and path of file/directory as first parameter e.g.

$(fstat d $@ /absolute_directory_path $)

The map implements three checks:

d - check if directory exits. It returns no match or "OK" string
f - check if file exits. It returns no match or "OK" string"
s - report file size. It return no match or size string

Install

Apply the patch (the gpg signature) - in main directory of sendmail distribtion execute
```
patch -p1 < fstat-8.12.11.patch
```
In devtools/Site/site.config.m4 add the following line:
```
APPENDDEF(`confMAPDEF',`-DFSTATMAP')dnl
```
Recompile and reinstall sendmail.

Tests

Add the following lines to *.mc file and generate new sendmail.cf:

LOCAL_CONFIG
Kfstat fstat
LOCAL_RULESETS
Scheck_fstat
R$-:$*  $: $(fstat $1 $@ $2 $)

Use the following commands for tests:

Directory presence test:

echo "check_fstat d:_absolute_directory_path_" | sendmail -bt -d60.5 -d21.12

File presence test:

echo "check_fstat f:_absolute_file_path_" | sendmail -bt -d60.5 -d21.12

File size test:

echo "check_fstat s:_absolute_file_path_" | sendmail -bt -d60.5 -d21.12

Additional

I created the map to allow real time checks if cyrus mailbox exists by checking presence of top level directory of the mailbox.

I think it may be used for the same purpose with other virtual mailbox (no OS account) servers.