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HP-UX 11i Version 3: February 2007

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ch_rc — change system configuration file


/usr/sbin/ch_rc -a|-r|-l [-v] [-A] [-R root] [-p {parameter|parameter=value}...] [file...]


ch_rc manages the addition, modification, removal, and retrieval of information stored in files having the format of those in the /etc/rc.config.d directory.

Parameter names are treated as strings. Thus, X[0] has no special meaning to ch_rc in relation to other parameters named X[1]orX.



Specify the file(s) to be used as the configuration database. If no file is specified, the set of files used by ch_rc defaults to /etc/TIMEZONE and all files in the /etc/rc.config.d directory.

Modification and deletion of configuration parameters occurs in the file where the parameter is found.


Add or modify a parameter definition. For each parameter specified on the command line, if the parameter is found in the specified (or default) files, it is modified to reflect the specified value. If the parameter is not found, it is added to the specified file(s).

If a new parameter is being defined, one or more files must be specified on the command line; the specified files are those in which the parameter will be defined.


Remove a parameter definition. For each parameter name specified on the command line, remove any occurrence of that parameter from the specified file(s).


List configuration values. For each parameter specified on the command line, output every definition of the parameter from the specified file(s). Output consists of only the values, one per line.


Specify a parameter name or name/value pair. If a name and value is expected, but only a name is specified, the value will be set to the empty string. For example, specifying FOO or FOO= will result in FOO and FOO= respectively.

Due to shell quoting rules, if you need a quoted parameter value, you must protect the quotes from the shell. For example,

ch_rc -a -p VALUE="a b c" <file>


VALUE=a b c

which is an error, whereas,

ch_rc -a -p VALUE='"a b c"' <file>


VALUE="a b c"


Verbose. When used with the -l option, the -v option causes a verbose listing to be output. This listing includes a filename followed by the entire line containing the specified parameter for each occurrance of the parameter.


The -A option is used to list all occurances of array parameters matching the parameters specified on the command line.

For example,

ch_rc -l -A -v -p ZZZ file

may emit the following output:

file: ZZZ[0]=zero file: ZZZ[5]=five file: ZZZ[9]=fred

-R root

Normally, the files specified on the command line are used as specified. By specifying a root directory with the -R option, all files (including the default files if none are specified) will be interpreted relative to root.

For example, if root is specified as /foo and /etc/TIMEZONE is specified on the command line, it will be interpreted as /foo/etc/TIMEZONE.


ch_rc exits with one of the following values:


add/delete/list successful


command line syntax/usage error


can not access one or more of the listed (or default) files


can not open/create/write file


memory error


no files specified on command line for add option


Files in the /etc/rc.config.d directory have the following format:

# Comments are preceded by pound signs and # are always on a line of their own. # Blank lines are allowed. VARIABLE=value VARIABLE_2=value2 VARIABLE_3[1]=value3 VARIABLE_3[2]=value4 # All parameters are defined on a single line # Parameters must not be exported


ch_rc does not interpret configuration files; it only does pattern matching. As a result, if comments appear on lines containing parameter definitions, the comments will also appear in output when using the -l option.

ch_rc cannot parse multiple parameter definitions which occur on the same line of a file.


ch_rc was developed by HP.



system configuration database driver file


directory containing system configuration files



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