Archivers
Archivers
ENiGMA½ can detect and process various archive formats such as zip and arj for a variety of tasks from file upload processing to EchoMail bundle compress/decompression. The archives section of config.hjson is used to override defaults, add new handlers, and so on.
Archivers are managed via the archives:archivers configuration block of config.hjson. Each entry in this section defines an external archiver that can be referenced in other sections of config.hjson and in code. Entries define how to compress, decompress (a full archive), list, and extract (specific files from an archive).
Generally you do not need to do anything beyond installing supporting binaries. No
config.hjsonediting necessary; Please see External Binaries!
Quick Check
On Linux, you can quickly check what is available in your PATH:
command -v 7za zip unzip lha unlzx arj unrar tar atr
Archiver Configuration
Archiver entries in config.hjson are mostly self explanatory with the exception of list commands that require some additional information. The args member for an entry is an array of arguments to pass to cmd. Some variables are available to args that will be expanded by the system:
-
{archivePath}(all): Path to the archive -
{fileList}(compress, extract): List of file(s) to compress or extract -
{extractPath}(decompress, extract): Path to extract to
For list commands, the entryMatch key must be provided. This key should provide a regular expression that matches two sub groups: One for uncompressed file byte sizes (sub group 1) and the other for file names (sub group 2). An optional entryGroupOrder can be supplied to change the default sub group order.
Example Archiver Configuration
7Zip: {
compress: {
cmd: '7za',
args: [ 'a', '-tzip', '{archivePath}', '{fileList}' ]
}
decompress: {
cmd: '7za',
args: [ 'e', '-y', '-o{extractPath}', '{archivePath}' ]
}
list: {
cmd: '7za',
args: [ 'l', '{archivePath}' ]
entryMatch: "^[0-9]{4}-[0-9]{2}-[0-9]{2}\\s[0-9]{2}:[0-9]{2}:[0-9]{2}\\s[A-Za-z\\.]{5}\\s+([0-9]+)\\s+[0-9]+\\s+([^\\r\\n]+)$",
}
extract: {
cmd: '7za',
args: [ 'e', '-y', '-o{extractPath}', '{archivePath}', '{fileList}' ]
}
}
Archive Formats
Archive formats are defined in the fileTypes configuration block (alongside other file types). ENiGMA½ detects archives by signature (and sometimes by extension) and then uses the archiveHandler value to select an entry from archives:archivers.
Many different types come pre-configured (see core/config_default.js).
Example archive file type mapping
'application/zip': {
desc: 'ZIP Archive'
sig: '504b0304' /* byte signature in HEX */
offset: 0
archiveHandler: 'InfoZip' /* points to a defined archiver */
}