3.9 mchgstr - Substitute String

Replace the field(s) specified in the f= parameter with the string according to the replacement criteria specified in the c= parameter.

Format

mchgstr c= f= [O=] [-A] [-F] [-sub] [-W] [i=] [o=] [-nfn] [-nfno] [-x] [--help] [--version]

Parameters

`c=`	Specify the replacement character string to be replaced.
`f=`	Specify the field(s) (multiple fields can be specified) where the character string is replaced
	according to the replacement criteria specified in the verb\|c=\| parameter.
`O=`	Specify the replacement string if the values does not match any substitution criteria specified in the `c=` parameter
	(returns NULL values when this parameter is not specified).
`-A`	This option adds output in a new column instead of replacing the specified item.
`-F`	Retain values in output even though values fall outside the specified numeric range defined in the R= parameter.
`-sub`	Compare using substring match rather than exact match.
	Search the values specified in the `f=` parameter,
	and replace the string with the criteria specified in `c=`.
`-W`	Match wide-character substring with `-sub` option.

Examples

Example 1: Basic Example

Replace values in the column from "01" to "A", "03" to "B", "04" to "C". Other values that do not match the criteria are returned as NULL values in the output.

$ more dat1.csv
id,item
1,01
2,02
3,03
4,04
5,05
$ mchgstr f=item c=01:A,03:B,05:C i=dat1.csv o=rsl1.csv
#END# kgchgstr c=01:A,03:B,05:C f=item i=dat1.csv o=rsl1.csv
$ more rsl1.csv
id,item
1,A
2,
3,B
4,
5,C

Example 2: Replace values outside the criteria

Use the O= parameter to replace character string that do not match the substitution criteria to "out of range" in the output.

$ mchgstr f=item c=01:A,03:B,05:C O="out of range" i=dat1.csv o=rsl2.csv
#END# kgchgstr O=out of range c=01:A,03:B,05:C f=item i=dat1.csv o=rsl2.csv
$ more rsl2.csv
id,item
1,A
2,out of range
3,B
4,out of range
5,C

Example 3: Example 3: Add new column in output

Define the name of new column (item info) in output with -A option.

$ mchgstr f=item:"item info" c=01:A,03:B,05:C O="out of range" -A i=dat1.csv o=rsl3.csv
#END# kgchgstr -A O=out of range c=01:A,03:B,05:C f=item:item info i=dat1.csv o=rsl3.csv
$ more rsl3.csv
id,item,item info
1,01,A
2,02,out of range
3,03,B
4,04,out of range
5,05,C

Example 4: Display original value in field falls outside the criteria

When -F option is specified, output value of the field remains the same if it does not match any of the substitution criteria.

$ mchgstr f=item c=01:A,03:B,05:C -F i=dat1.csv o=rsl4.csv
#END# kgchgstr -F c=01:A,03:B,05:C f=item i=dat1.csv o=rsl4.csv
$ more rsl4.csv
id,item
1,A
2,02
3,B
4,04
5,C

Example 5: Replace matching substrings

Replace substring with -sub option specified. In following example, values where item field contains "01" will be substituted with "A".

$ more dat2.csv
id,item
1,0111
2,0121
3,0231
4,0241
5,0151
$ mchgstr f=item c=01:A -sub i=dat2.csv o=rsl5.csv
#END# kgchgstr -sub c=01:A f=item i=dat2.csv o=rsl5.csv
$ more rsl5.csv
id,item
1,A11
2,A21
3,
4,
5,A51

Example 6: Wide character substring match

Use the option -W to replace wide-characters strings. However, if you are using UTF-8 encoding, it is not necessary to define -W. Refer to the section "Multibyte characters" for details.

$ more dat3.csv
id,city
1,奈良市
2,下市町
3,十津川村
4,五條市
5,山添村
$ mchgstr f=city c=市:01,町:02,村:02 -sub -W i=dat3.csv o=rsl6.csv
#END# kgchgstr -W -sub c=市:01,町:02,村:02 f=city i=dat3.csv o=rsl6.csv
$ more rsl6.csv
id,city
1,奈良01
2,下0102
3,十津川02
4,五條01
5,山添02

Related Commands

mchgnum : Substitution based on numeric range.

msed : Replace string by regular expression.