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#
Database Utilities

The Source-Navigator utilities `dbdump`, `dbcp`, and `dbimp` access and maintain databases that can be started from user shells or applications. These utilities are located in the `.../bin` directory.

### Note

The scripts in this chapter are written to work under the UNIX operating system. When running under DOS, the scripts must be changed.

## dbdump

The `dbdump` utility provides a complete listing, or a dump, of the contents of a database table. Its usage is:

    dbdump ?-separator char? file

`dbdump` separates the key and data parts with a semicolon (`;`). The hash character (`#`) and brackets (`{}`) indicate an empty field. The shell script below lists the name and locations of the project class.

    #!/bin/sh

    dbdump=$HOME/snavigator/bin/dbdump
    project=tmp

    $dbdump -s ' ' $project.cl | awk '{printf
        "%s,%s,%s\n",$1,$3,$2}'

## dbcp

The `dbcp` utility copies and compacts the database. Space freed up by deleting key/data pairs from `btree` tables is never reclaimed, although it is normally made available for reuse. When copying a database with `dbcp`, deleted records are not copied, resulting in a much better page-fill factor and reduced disk space requirements. Its usage is:

    dbcp input_table output_table

The following shell script compresses the tables of a Source-Navigator project.

    #!/bin/sh

    execdir=$HOME/snavigator/bin
    dbcp=$execdir/dbcp

    project=TEST
    cd .paf

    for i in $project.[a-z]*
    do
      $dbcp $i $$.tmp
      mv $$.tmp $i
    done

You can use this script even for currently-running Source-Navigator projects because compressing database tables does not affect performance. Hash tables may also be copied with `dbcp`, but there will be no space savings.

## dbimp

The `dbimp` utility inserts, updates, and deletes records in a project database. It reads commands from its standard input.

Its usage is:

    dbimp ?-c cache_size? ?-C cross_cache_size?
              ?-l? ?-f file? db_prefix

References to local variables are stored only if the `-l` flag is specified.

`db_prefix` contains the name of the database directory, for example, `.sn` and the base name of the project file. If the project file is called `test.proj`, `db_prefix` could be called `.snprj/test`.

The format of the commands (read from standard input) must follow this syntax:

    COMMAND;KEY;DATA

If `COMMAND` is greater than or equal to 0, `dbimp` inserts KEY/DATA pairs. The value of `COMMAND` must be between `PAF_FILE` and `PAF_COMMENT_DEF`, inclusive. (For the numerical values see `sn.h`.)

The following example inserts a function (`strcopy`) definition.

    8;strcopy 000001.004 x.c;4.1 0x0 {int} {} {} {}

The following example inserts a method definition (`pro3`) of the class `xharom`.

    17;xharom pro3 000036.005 x.C;36.11 0x2 {int} {} {} {}

The instructions below insert cross-references (Refers-to and Referred-by) into the project database. The ? symbol represents the `sn_sep` separator character in the instructions below.

    16;#?abc?fu?abc?var?lv?w?000004?x.c;#
    15;abc?var?lv?#?abc?fu?w?000004?x.c;#
    16;#?abc?fu?#?hello?fu?p?000005?x.c;#
    15;#?hello?fu?#?abc?fu?p?000005?x.c;#

See Database Table Structures for information on the structure of the Source-Navigator database tables.

- If `COMMAND` is 0, `KEY` must contain a known source file name of the project, and `dbimp` deletes the definitions of, but not cross-references to, the file.

- If `COMMAND` is -1, `KEY` must be 0 and `DATA` must contain a known source file name of the project, and `dbimp` deletes the definitions of, but not cross-references to, the file.

- If `COMMAND` is -2, `KEY` must be 0 and `DATA` must contain a known source file name of the project, and `dbimp` deletes the cross-references to, but not definitions of, the file.

The following example deletes the cross-reference information for the file `x.c`:

    -2;0;x.c

### Limitations

Undefined results occur if the `COMMAND` does not have a legal value.

In the commands, you may use only single blank spaces and no tabs.

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