db allows manipulation of
btree(3) and
hash(3) (
db(3)) databases.
db has three modes of operation to perform upon
dbfile:
read
Displays the given keys, and keys described in infile. If no keys and no infile is specified, the entire database is displayed. This is the default mode of operation.
delete
Enabled with -d. Deletes the given keys, and keys described in infile.
write
Enabled with -w. Writes the given keys and values, and keys and values described in infile (in the latter case, entries are separated by insep).
There are two mandatory arguments:
type is the database type; either ‘
btree' or ‘
hash', and
dbfile is the database file to manipulate.
Options valid for all modes are:
-E endian
Set the endianness of the database.
endian may be one of:
Defaults to ‘H' (host endian).
-f infile
Contains a list of keys (for read and delete), or insep separated keys and values (for write) to be used as arguments to the given mode. If infile is ‘-', stdin is used.
-i
Keys are converted to lower case before manipulation.
-N
Do not include the NUL byte at the end of the key or value.
-q
Quiet operation. In read mode, missing keys are not considered to be an error. In delete (-d) and write (-w) modes, the result of various operations is suppressed.
-T visspec
Control how the items specified by the
-S option are encoded and
-U option are decoded. The
visspec option-argument is a string specifying
strsvisx(3) flags. The string consists of one or more characters:
c
VIS_CSTYLE. Overrides h and o.
h
VIS_HTTPSTYLE. Overrides c and o.
o
VIS_OCTAL. Overrides c and h.
-U only supports
-T h.
See
vis(1)'s corresponding options for the meaning of these characters, and
strsvisx(3) for more detail on the flags.
-U unvisitem
Specify items to
strunvisx(3) decode. The
unvisitem option-argument is a character specifying if the key (
k), the value (
v) or both (
b) should be decoded.
Read mode specific options are:
-D
Display duplicate entries in btree databases.
-O outsep
Field separator string between key and value. Defaults to a single tab (‘\t').
-S visitem
Specify items to
strsvisx(3) encode. The
visitem option-argument is a character specifying if the key (
k), the value (
v) or both (
b) should be encoded.
-X extravis
When encoding items with
-S option also encode characters in
extravis, per
strsvisx(3).
(If neither of -K or -V is given, both options are enabled.)
Write mode specific options are:
-C
Create new database, and truncate existing databases.
-D
Allow duplicate entries in btree databases. (Requires -R to be useful.)
-F insep
Input field separator string between key and value used when parsing infile. Defaults to a single space (‘ ').
-m mode
Octal mode of created database. Defaults to ‘0644'.
-P pagesize
Set the page size of the table to pagesize bytes. If set to ‘0', a database-specific default is determined, based on the block-size of the underlying file-system. Defaults to ‘4096'.
-R
Overwrite existing entries. If not specified, writing to an existing entry raises an error.