MX Utility

MX is the general-purpose utility for CDS/ISIS databases (CISIS). It acts as the "Swiss Army Knife" of the suite, capable of reading, writing, filtering, formatting, and exporting data.

Unlike other specific tools (like id2i or mst2iso), MX unifies almost all operations in a single executable. It allows free-text searches even without an inverted file and can perform complex data transformations on the fly.

Basic Syntax

Execution without parameters shows the help screen and version:

mx [cipar=<file>] [db=]<database> [parameters...]

Full Parameter List

Based on the official help output, here are the available parameters grouped by function:

Parameter	Description
Input/Output
db=<name>	The master file (database) to read from.
iso=<file>	Input or Output ISO-2709 file.
in=<file>	Input text file (optional alternative to DB).
out=<file>	Output text file (redirects standard output).
create=<name>	Creates a new database with the records processed.
append=<name>	Appends records to an existing database.
copy=<name>	Copies records to another database (similar to create/append).
Selection & filtering
from=<mfn>	Start processing from this MFN.
to=<mfn>	Stop processing at this MFN.
count=<n>	Process a maximum of n records.
bool=<expr>	Filter records using a Boolean expression (Search).
Processing
pft=<format>	Apply a PFT format to the output.
proc=<format>	Apply a modification procedure (add/delete fields) in memory.
gizmo=<db>	Apply a global search/replace using a Gizmo database.
join=<db>	Merge data from another database.
System
cipar=<file>	Path to the configuration file mapping database paths.
tell=<n>	Display progress status every n records processed.
-all	Process deleted records (logically deleted records are usually skipped).
now	Suppress "Press any key" prompts (Batch mode).

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Core Operations

1. Import & Export (ISO-2709)

MX converts records between Master Files (.mst) and the exchange format ISO-2709.

• Export to ISO:

mx mydb iso=output.iso -all now

Tip: Append parameters to iso= to modify the format.

• iso=output.iso,marc: Creates a MARC-tagged ISO (tags 1-999).

• iso=output.iso,linux: Uses Line Feed (LF) instead of CRLF.

• Import from ISO:

/* Create a new database */
mx iso=input.iso create=newdb -all now

/* Append to existing database */
mx iso=input.iso append=existingdb -all now

2. Database Maintenance

• Copying a Database: Useful for backups or compacting (removing deleted records).

mx db=source create=backup -all now

• Modifying Records (Proc): The proc parameter allows you to manipulate fields on the fly using the formatting language.

/* Delete tag 50 and add tag 99 */
mx mydb "proc='d50a99~New Data~'" copy=newdb

3. Filtering and Searching

MX can filter records sequentially or using the inverted file.

• Sequential Search (No Index needed): Using the p (presence) or val commands in a conditional PFT.

mx mydb "pft=if p(v10) then mfn/ fi" now

• Boolean Search (Uses Index): Uses the bool parameter.

mx mydb "bool=WATER * SOIL" iso=subset.iso

4. Joining Databases

Merges data from another database into the current stream based on a common key.

• Syntax: join=<db>:<format_key>=<format_display>
• Example: Join users database into loans where v10 in loans matches the key in users.

mx loans join=users:v10="User Name: "v20

5. Global Changes (Gizmo)

Uses a dictionary database to replace strings globally.

• Syntax: gizmo=<gizmo_db>,<taglist>
• Usage: Useful for cleaning up authority lists (e.g., changing "USA" to "United States" in all records automatically).

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Inverted File Generation

While fullinv is the dedicated tool for indexing, mx can also generate Inverted Files (.ifp, .cnt, .n01, etc.). This is often preferred in scripts because mx is more robust.

Syntax:

mx <db> fst=@<fst_file> fullinv=<db_name> [actab=...] [uctab=...] -all now

Parameters:

• fst=@file.fst: The path to the Field Selection Table.
• fullinv=<name>: The name of the inverted file to create (usually matches the DB name).
• actab/uctab: Character conversion tables (optional but recommended for ANSI/UTF-8 consistency).
• tell=100: Show progress every 100 records.

Example:

mx cds fst=@cds.fst fullinv=cds -all now tell=100

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Q&A / Common Issues

Exporting tags > 3000

The original ISO-2709 standard limits tags to 3 digits (001-999). CISIS supports 4 or 5 digits, but exporting them to ISO requires special handling.

• Problem: Tags like 3000 might be truncated or ignored in standard ISO export.
• Solution: Use the parameter outisotag1=<tag>.

mx mydb iso=output.iso outisotag1=3000 now

This forces MX to treat tags starting from 3000 correctly in the extension block.

Unix vs. Windows Line Breaks

When moving data between Linux and Windows, line endings in ISO files can cause issues.

• Use iso=filename,linux to force LF (Unix style).
• Use iso=filename,dos to force CRLF (Windows style).