| 1 | .\" Copyright (c) 1999 Tim Singletary
|
|---|
| 2 | .\" No copyright is claimed.
|
|---|
| 3 | .\"
|
|---|
| 4 | .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|---|
| 5 | .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|---|
| 6 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|---|
| 7 | .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|---|
| 8 | .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|---|
| 9 | .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|---|
| 10 | .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|---|
| 11 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|---|
| 12 | .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|---|
| 13 | .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|---|
| 14 | .\" SUCH DAMAGE.
|
|---|
| 15 | .\"
|
|---|
| 16 | .\" $FreeBSD: src/lib/libc/db/man/dbm.3,v 1.7 2002/12/19 09:40:21 ru Exp $
|
|---|
| 17 | .\"
|
|---|
| 18 | .\" Note: The date here should be updated whenever a non-trivial
|
|---|
| 19 | .\" change is made to the manual page.
|
|---|
| 20 | .Dd July 7, 1999
|
|---|
| 21 | .Dt DBM 3
|
|---|
| 22 | .Os
|
|---|
| 23 | .Sh NAME
|
|---|
| 24 | .Nm dbm_clearerr ,
|
|---|
| 25 | .Nm dbm_close ,
|
|---|
| 26 | .Nm dbm_delete ,
|
|---|
| 27 | .Nm dbm_dirfno ,
|
|---|
| 28 | .Nm dbm_error ,
|
|---|
| 29 | .Nm dbm_fetch ,
|
|---|
| 30 | .Nm dbm_firstkey ,
|
|---|
| 31 | .Nm dbm_nextkey ,
|
|---|
| 32 | .Nm dbm_open ,
|
|---|
| 33 | .Nm dbm_store
|
|---|
| 34 | .Nd database access functions
|
|---|
| 35 | .Sh SYNOPSIS
|
|---|
| 36 | .In fcntl.h
|
|---|
| 37 | .In ndbm.h
|
|---|
| 38 | .Ft DBM *
|
|---|
| 39 | .Fn dbm_open "const char *base" "int flags" "int mode"
|
|---|
| 40 | .Ft void
|
|---|
| 41 | .Fn dbm_close "DBM *db"
|
|---|
| 42 | .Ft int
|
|---|
| 43 | .Fn dbm_store "DBM *db" "datum key" "datum data" "int flags"
|
|---|
| 44 | .Ft datum
|
|---|
| 45 | .Fn dbm_fetch "DBM *db" "datum key"
|
|---|
| 46 | .Ft int
|
|---|
| 47 | .Fn dbm_delete "DBM *db" "datum key"
|
|---|
| 48 | .Ft datum
|
|---|
| 49 | .Fn dbm_firstkey "DBM *db"
|
|---|
| 50 | .Ft datum
|
|---|
| 51 | .Fn dbm_nextkey "DBM *db"
|
|---|
| 52 | .Ft int
|
|---|
| 53 | .Fn dbm_error "DBM *db"
|
|---|
| 54 | .Ft int
|
|---|
| 55 | .Fn dbm_clearerr "DBM *db"
|
|---|
| 56 | .Ft int
|
|---|
| 57 | .Fn dbm_dirfno "DBM *db"
|
|---|
| 58 | .Sh DESCRIPTION
|
|---|
| 59 | Database access functions.
|
|---|
| 60 | These functions are implemented using
|
|---|
| 61 | .Xr dbopen 3
|
|---|
| 62 | with a
|
|---|
| 63 | .Xr hash 3
|
|---|
| 64 | database.
|
|---|
| 65 | .Pp
|
|---|
| 66 | .Vt datum
|
|---|
| 67 | is declared in
|
|---|
| 68 | .Aq Pa ndbm.h :
|
|---|
| 69 | .Bd -literal
|
|---|
| 70 | typedef struct {
|
|---|
| 71 | char *dptr;
|
|---|
| 72 | int dsize;
|
|---|
| 73 | } datum;
|
|---|
| 74 | .Ed
|
|---|
| 75 | .Pp
|
|---|
| 76 | The
|
|---|
| 77 | .Fn dbm_open base flags mode
|
|---|
| 78 | function
|
|---|
| 79 | opens or creates a database.
|
|---|
| 80 | The
|
|---|
| 81 | .Fa base
|
|---|
| 82 | argument
|
|---|
| 83 | is the basename of the file containing
|
|---|
| 84 | the database; the actual database has a
|
|---|
| 85 | .Pa .db
|
|---|
| 86 | suffix.
|
|---|
| 87 | I.e., if
|
|---|
| 88 | .Fa base
|
|---|
| 89 | is
|
|---|
| 90 | .Qq Li /home/me/mystuff
|
|---|
| 91 | then the actual database is in the file
|
|---|
| 92 | .Pa /home/me/mystuff.db .
|
|---|
| 93 | The
|
|---|
| 94 | .Fa flags
|
|---|
| 95 | and
|
|---|
| 96 | .Fa mode
|
|---|
| 97 | arguments
|
|---|
| 98 | are passed to
|
|---|
| 99 | .Xr open 2 .
|
|---|
| 100 | .Pq Dv O_RDWR | O_CREAT
|
|---|
| 101 | is a typical value for
|
|---|
| 102 | .Fa flags ;
|
|---|
| 103 | .Li 0660
|
|---|
| 104 | is a typical value for
|
|---|
| 105 | .Fa mode .
|
|---|
| 106 | .Dv O_WRONLY
|
|---|
| 107 | is not allowed in
|
|---|
| 108 | .Fa flags .
|
|---|
| 109 | The pointer returned by
|
|---|
| 110 | .Fn dbm_open
|
|---|
| 111 | identifies the database and is the
|
|---|
| 112 | .Fa db
|
|---|
| 113 | argument to the other functions.
|
|---|
| 114 | The
|
|---|
| 115 | .Fn dbm_open
|
|---|
| 116 | function
|
|---|
| 117 | returns
|
|---|
| 118 | .Dv NULL
|
|---|
| 119 | and sets
|
|---|
| 120 | .Va errno
|
|---|
| 121 | if there were any errors.
|
|---|
| 122 | .Pp
|
|---|
| 123 | The
|
|---|
| 124 | .Fn dbm_close db
|
|---|
| 125 | function
|
|---|
| 126 | closes the database.
|
|---|
| 127 | The
|
|---|
| 128 | .Fn dbm_close
|
|---|
| 129 | function
|
|---|
| 130 | normally returns zero.
|
|---|
| 131 | .Pp
|
|---|
| 132 | The
|
|---|
| 133 | .Fn dbm_store db key data flags
|
|---|
| 134 | function
|
|---|
| 135 | inserts or replaces an entry in the database.
|
|---|
| 136 | The
|
|---|
| 137 | .Fa flags
|
|---|
| 138 | argument
|
|---|
| 139 | is either
|
|---|
| 140 | .Dv DBM_INSERT
|
|---|
| 141 | or
|
|---|
| 142 | .Dv DBM_REPLACE .
|
|---|
| 143 | If
|
|---|
| 144 | .Fa flags
|
|---|
| 145 | is
|
|---|
| 146 | .Dv DBM_INSERT
|
|---|
| 147 | and the database already contains an entry for
|
|---|
| 148 | .Fa key ,
|
|---|
| 149 | that entry is not replaced.
|
|---|
| 150 | Otherwise the entry is replaced or inserted.
|
|---|
| 151 | The
|
|---|
| 152 | .Fn dbm_store
|
|---|
| 153 | function
|
|---|
| 154 | normally returns zero but returns 1 if the entry could not be
|
|---|
| 155 | inserted (because
|
|---|
| 156 | .Fa flags
|
|---|
| 157 | is
|
|---|
| 158 | .Dv DBM_INSERT ,
|
|---|
| 159 | and an entry with
|
|---|
| 160 | .Fa key
|
|---|
| 161 | already exists) or returns -1 and sets
|
|---|
| 162 | .Va errno
|
|---|
| 163 | if there were any errors.
|
|---|
| 164 | .Pp
|
|---|
| 165 | The
|
|---|
| 166 | .Fn dbm_fetch db key
|
|---|
| 167 | function
|
|---|
| 168 | returns
|
|---|
| 169 | .Dv NULL
|
|---|
| 170 | or the
|
|---|
| 171 | .Fa data
|
|---|
| 172 | corresponding to
|
|---|
| 173 | .Fa key .
|
|---|
| 174 | .Pp
|
|---|
| 175 | The
|
|---|
| 176 | .Fn dbm_delete db key
|
|---|
| 177 | function
|
|---|
| 178 | deletes the entry for
|
|---|
| 179 | .Fa key .
|
|---|
| 180 | The
|
|---|
| 181 | .Fn dbm_delete
|
|---|
| 182 | function
|
|---|
| 183 | normally returns zero but returns 1 if there was no entry with
|
|---|
| 184 | .Fa key
|
|---|
| 185 | in the database or returns -1 and sets
|
|---|
| 186 | .Va errno
|
|---|
| 187 | if there were any errors.
|
|---|
| 188 | .Pp
|
|---|
| 189 | The
|
|---|
| 190 | .Fn dbm_firstkey db
|
|---|
| 191 | function
|
|---|
| 192 | returns the first key in the database.
|
|---|
| 193 | The
|
|---|
| 194 | .Fn dbm_nextkey db
|
|---|
| 195 | function
|
|---|
| 196 | returns subsequent keys.
|
|---|
| 197 | The
|
|---|
| 198 | .Fn db_firstkey
|
|---|
| 199 | function
|
|---|
| 200 | must be called before
|
|---|
| 201 | .Fn dbm_nextkey .
|
|---|
| 202 | The order in which keys are returned is unspecified and may appear
|
|---|
| 203 | random.
|
|---|
| 204 | The
|
|---|
| 205 | .Fn dbm_nextkey
|
|---|
| 206 | function
|
|---|
| 207 | returns
|
|---|
| 208 | .Dv NULL
|
|---|
| 209 | after all keys have been returned.
|
|---|
| 210 | .Pp
|
|---|
| 211 | The
|
|---|
| 212 | .Fn dbm_error db
|
|---|
| 213 | function
|
|---|
| 214 | returns the
|
|---|
| 215 | .Va errno
|
|---|
| 216 | value of the most recent error.
|
|---|
| 217 | The
|
|---|
| 218 | .Fn dbm_clearerr db
|
|---|
| 219 | function
|
|---|
| 220 | resets this value to 0 and returns 0.
|
|---|
| 221 | .Pp
|
|---|
| 222 | The
|
|---|
| 223 | .Fn dbm_dirfno db
|
|---|
| 224 | function
|
|---|
| 225 | returns the file descriptor to the database.
|
|---|
| 226 | .Sh SEE ALSO
|
|---|
| 227 | .Xr open 2 ,
|
|---|
| 228 | .Xr dbopen 3 ,
|
|---|
| 229 | .Xr hash 3
|
|---|
| 230 | .Sh STANDARDS
|
|---|
| 231 | These functions (except
|
|---|
| 232 | .Fn dbm_dirfno )
|
|---|
| 233 | are included in the
|
|---|
| 234 | .St -susv2 .
|
|---|
