cjoin0(USP)

Name

cjoin0 : Sequential key matching select

Synopsis

Usage   : cjoin0 key=<key> <master> <tran>

Options : +ng[<fd>]

          -e

          -s<c>

Version : Tue Jan  9 09:02:34 JST 2024

Edition : 1

Description

Selects all records from <tran> where the <key> fields match

corresponding fields of <master>.

The <key> fields in <master> MUST be sorted.  Also, the key fields

in <master> must only contain unique values (the same value cannot

be repeated in the <key> fields).

<key> designates the field position as fllows:

single field       2        the 2nd field

                   NF   the last field

                   NF-1   the field just before the last field

contiguous fields  2/4      from the 2nd field to the 4th field

                   4/2   from the 4th field to the 2nd field

                   NF-3/NF  from NF-3 field to the NF field

combination        2@NF     the 2nd field and the NF field

There is no limit on the length of the key field or on the number

of key fields.  The key field can also contain multi-byte characters

such as Japanese.

If you specify "r" as comparison method after the field position,

the fields are compared in reverse order.  If you specify "n" as

comparison method after the field position, that field's values will

be compared as numbers.  If you specify "nr" as comparison method

after the field, the values will be compared in reverse order as

numbers.  If you specify comparison method before or after the "/",

you must use the same comparison method for both fields.

  2n/5n     OK

  2n/5nr    Error

  2n/5r     Error

When you specify "e" as comparison method or specify -e ootion and no

method, characters in the field are replaced as follows and compared

as string:

  _  ==> 0x20 (space)

  \0 ==> 0x00 (null)

  \t ==> 0x09 (tab stop)

  \n ==> 0x0a (new line)

  \r ==> 0x0d (carrige return)

  \_ ==> 0x5f (underscore)

  \\ ==> 0x5c (back slash)

In all cases, the master must be sorted for the specified key. (The

transaction file need not be sorted).

If the file name is omitted or if it is specified as "-" then the

command will read from standard input.

cjoin0 reads the entire <master> file into memory, so if <master>

is extremely large a memory allocation error can occur.  On the contrary,

when <master> is relatively small and <tran> is extremely large,

using cjoin0 is most efficient.

Example 1 Normal Usage

$ cat master

0000003 Wilson_____ 26 F

0000005 Hawking____ 50 F

0000007 Newton______ 42 F

$ cat tran

0000005 82 79 16 21 80

0000001 46 39 8  5 21

0000004 58 71 20 10 6

0000009 60 89 33 18 6

0000003 30 50 71 36 30

0000007 50 2  33 15 62

$ cjoin0 key=1 master tran > ok

$ cat ok

0000005 82 79 16 21 80

0000003 30 50 71 36 30

0000007 50 2  33 15 62

Example 2 Usage of +ng option

$ cjoin0 +ng key=1 master tran > ok 2> ng

$ cat ng

0000001 46 39 8  5 21

0000004 58 71 20 10 6

0000009 60 89 33 18 6

Example 3 Read from standard input

$ cat tran | cjoin0 +ng key=1 master > ok 2> ng

$ cat tran | cjoin0 +ng key=1 master - > ok 2> ng

$ cat master | cjoin0 +ng key=1 - tran > ok 2> ng