2.10 Environment Variable

Shell environment variable can be set in MCMD to customize the settings for commands. The environment variables that can be set for MCMD are listed in Table 2.5.

Table 2.5: List of the environment variable to configure KGMOD

Variable name	Default value	Description
`KG_iSize`	4096000	Size of data read for each time
		Four times of `KG_iSize` is allocated for input buffer.
		However, 10 times of the command parameters is allocated for kgsortf.
		Refer to `KG_BlockCount` for command’s buffer size on processing by key block.
		The following conditions must be satisfied.
		`KG_iSize`=`KG_MaxRecLen` $*$ i (given i is an integer greater than 1)
		`KG_iSize` $\ge$ `KG_MaxRecLen` $*$ 2
`KG_oSize`	2048000	Size of data written for each time
		The same memory size in `KG_oSize` is allocated for output buffer.
		`KG_oSize`=`KG_MaxRecLen` $*$ i (given i is an integer greater than 1)
		`KG_oSize` $\ge$ `KG_MaxRecLen` $*$ 2
`KG_MaxRecLen`	1024000	The maximum number of characters per row (maximum:10240000)
		It must satisfy the conditions shown in `KG_iSize` and `KG_oSize`.
`KG_BlockCount`	128	The number of buffers required when processing $^{1)}$ by key.
		The column `KG_iSize` shows buffer size $*$ `KG_BlockCount` is allocated.
		`KG_MaxRecLen` $$ 2 + 4 $$ `KG_ioSize`) $*$ `KG_BlockCount`
`KG_TmpPath`	/tmp	The directory of temporary files in the default directory used by library functions.
`KG_Precision`	10	Significant figures
`KG_VerboseLevel`	4	Output error message for M-Command
		0: Do not print any messages.
		1: + error message output
		2: + warning message output
		3: + end message output
		4: + msg message output (default)

Note 1) Processing by key, such as mnjoin, refers to reading data with same key into the memory at once. Refer to the manual of corresponding command for more details.

Below is an example of changing the settings of KG_VerboseLevel to control the command message.

Examples

Example 1: End message

The default setting of output message is set as KG_Verbose=4 which displays a message when the program finished processing normally or terminates upon an error.

$ more dat.csv
k,v
A,1
B,2
$ mcut f=k,v i=dat.csv o=out.csv
#END# kgcut f=k,v i=dat.csv o=out.csv
$ mcut x=k,v i=dat.csv o=out.csv
#ERROR# unknown parameter x= (kgcut)

Example 2: Only display error messages

If KG_Verbose=1, the stop error message is displayed, but not the normal exit message.

$ export KG_VerboseLevel=1
$ mcut f=k,v i=dat.csv o=out.csv
$ mcut x=k,v i=dat.csv o=out.csv
#ERROR# unknown parameter x= (kgcut)

Example 3: Do not display any messages

If KG_Verbose=0, no message will be displayed.

$ export KG_VerboseLevel=0
$ mcut f=k,v i=dat.csv o=out.csv
$ mcut x=k,v i=dat.csv o=out.csv