cdb_successor(3) Library Functions Manual cdb_successor(3)NAME
cdb_successor - find next record
SYNTAX
#include <cdb.h>
int cdb_successor(struct cdb *c,char *key,unsigned long int klen);
DESCRIPTION
cdb_successor finds the record that follows key. If key is NULL, cdb_successor finds the first record.
NOTE! The database must not contain keys with more than one associated record or this API will lead to infinite loops! Use cdb_firstkey
and cdb_nextkey instead.
You can use cdb_datapos or cdb_keypos to get position and cdb_datalen and cdb_keylen to get len.
SEE ALSO cdb_firstkey(3), cdb_nextkey(3)cdb_successor(3)
Check Out this Related Man Page
CDB(5) BSD File Formats Manual CDB(5)NAME
cdb -- format of the constant database
DESCRIPTION
The cdb database format provides a space-efficient (key,value) database. The format doesn't allow updates in any convenient form. The file
overhead is around 5 bytes per key and 5 bytes per entry. Keys are not stored and it is the responsibility of the caller to validate
matches. The index structure is based on a minimal perfect hash table, so exactly one entry has to be checked for a match.
General Format
The header record of a cdb database consists of the following:
struct header_cdb {
uint8_t magic[7];
uint8_t version;
uint8_t description[16];
uint32_t data_size;
uint32_t entries;
uint32_t entries_index;
uint32_t seed;
};
All fields are in Little Endian byte order.
This is followed by a description of the hash function of entries_index records. The size of each index entry is the logarithm of entries to
base 256, rounded up.
The index records are followed by the start offsets of the entries, followed by data_size. The offsets are relative to the end of the offset
record table and are monotically increasing. The size of each offset record is the logarithm of data_size to base 256, rounded up.
The offset table is followed by the entries in order. No separation or padding is added.
Limitations
The cdb file format is by design intended for a database that can be mapped into memory. The hard limit for the number of entries and keys
is 3435973836. The total size of all values must be smaller than 4GiB.
SEE ALSO cdbr(3), cdbw(3)HISTORY
Support for the cdb format first appeared in NetBSD 6.0.
AUTHORS
The cdbr and cdbw functions have been written by Joerg Sonnenberger <joerg@NetBSD.org>.
BSD April 27, 2010 BSD
I have a huge matrix file containing some 1.5 million rows and 6000 columns. The matrix looks something like this:
1 2 3
4 5 6
7 8 9
3 4 5
I want to add all the numbers in the columns of this matrix and display the result to my stdout. This means that the numbers in the first column are:
... (2 Replies)
Hi,
Just trying to get to grips with sed and awk for some reporting for work and I need some assistance:
I have a file that lists policy names on the first line and then on the second line whether the policy is active or not.
Policy Name: Policy1
Active: yes
Policy... (8 Replies)
version info :
vi availabe with RHEL 5.4
I have a text file with 10,000 lines. I want to copy lines from 5000th line to 7000th and redirect to a file. Any idea how I can do this?
Note:
The above scenario is just an example. In my actual requirement, the file has 14 million lines and I want... (9 Replies)
Hi everyone,
I know the following questions are noobish questions but I am asking them because I am confused about the basics of history behind UNIX and LINUX.
Ok onto business, my questions are-:
Was/Is UNIX ever an open source operating system ?
If UNIX was... (21 Replies)
Hello,
I couldn't find an actual introduction thread, so I decided to just put this here.
I go by d0wngrade online. I have been programming in multiple languages for about 15+ years. I started with standard web design languages like HTML and CSS, but I then advanced from design to development... (2 Replies)
Hi guys...
The first active code line in AudioScope.sh is set -u .
This causes a complete exit if a variable is used/found but has not been allocated at the start of the program.
However, apart from writing code to do the task, is there a switch to to check which variables have been... (17 Replies)
Hi.
In thread https://www.unix.com/shell-programming-and-scripting/267833-grouping-counting.html rovf and I had a mini-discussion on grep and awk.
Here is a demo script that compares the awk and grep approaches for this single problem:
#!/usr/bin/env bash
# @(#) s2 Demonstrate group... (1 Reply)
Hello,
I have to fish out some specific columns from a file based on the header value. I have the list of columns I need in a different file. I thought I could read in the list of headers I need,
# file with header names of required columns in required order
headers_file=$2
# read contents... (11 Replies)
For those interested in installing dash shell on OSX Lion to help test POSIX compliancy of shell scripts, it is quite easy. I did it like this:
If you don't have gcc on your system:
0. Download and install the Command Line Tools for Xcode package from Sign In - Apple *
1. Download the dash... (2 Replies)
Hello and thanks in advance for any help anyone can offer me
I'm trying to learn the find command and thought I was understanding it... Apparently I was wrong. I was doing compound searches and I started getting weird results with the -size test. I was trying to do a search on a 1G file owned by... (14 Replies)
I have data of an excel files as given below,
file1
org1_1 1 1 2.5 100
org1_2 1 2 5.5 98
org1_3 1 3 7.2 88
file2
org2_1 1 1 2.5 100
org2_2 1 2 5.5 56
org2_3 1 3 7.2 70
I have multiple excel files as above shown.
I have to copy column 1, column 4 and paste into a new excel file as... (26 Replies)
Dear All,
Taking a break from Vue.js coding for the site, SEO and YT videos; and hopefully addressing some well deserved criticism from some here that I have been too focused on the visual aspects of the forums versus the substance and the community....
While the "current generation... (9 Replies)
Hi all...
Well guys and gals, I jumped in at the deep end and found things that PERL cannot do by default.
Many tricky terminal escape codes are not catered for so I had to create workarounds.
One thing I searched for was this:
Passing perl variable to shell command
AND, @Neo this was... (15 Replies)