Installing and Using ldapsearch on Scientific Linux: A Complete Guide for LDAP Queries


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To perform LDAP queries on Scientific Linux, you'll need the ldapsearch utility, which is part of the openldap-clients package. Scientific Linux, being a RHEL-derived distribution, uses the same package management system as CentOS and RHEL.

There are two primary ways to install ldapsearch on Scientific Linux:

# Method 1: Using yum (recommended for Scientific Linux 6)
sudo yum install openldap-clients

# Method 2: Using dnf (for Scientific Linux 7+)
sudo dnf install openldap-clients

After installation, verify that ldapsearch is available:

which ldapsearch
ldapsearch -V

Here are some practical examples of using ldapsearch:

# Simple anonymous query
ldapsearch -x -H ldap://ldap.example.com -b "dc=example,dc=com"

# Authenticated query
ldapsearch -x -H ldap://ldap.example.com -D "cn=admin,dc=example,dc=com" -W -b "dc=example,dc=com"

# Specific attribute search
ldapsearch -x -H ldap://ldap.example.com -b "dc=example,dc=com" "(uid=johndoe)" cn mail

# Using SSL/TLS
ldapsearch -x -H ldaps://ldap.example.com -b "dc=example,dc=com" -ZZ

If you encounter problems, check these common solutions:

# If you get "No such file or directory" for ldapsearch:
sudo yum whatprovides */ldapsearch

# For SSL/TLS certificate issues:
export LDAPTLS_REQCERT=never

For frequent LDAP queries, consider creating a ~/.ldaprc file:

BASE dc=example,dc=com
URI ldap://ldap.example.com
TLS_CACERT /etc/ssl/certs/ca-bundle.crt

This will save you from typing common parameters repeatedly.

If openldap-clients isn't available in your repositories, you can try:

sudo yum install epel-release
sudo yum install openldap-clients

Or compile from source if necessary.

To perform LDAP queries on Scientific Linux, you'll need the ldapsearch utility which is part of the OpenLDAP client package. Scientific Linux (being RHEL-based) typically includes this in its default repositories.

The most straightforward way to install ldapsearch is through yum (or dnf on newer versions):

sudo yum install openldap-clients

For systems with dnf package manager:

sudo dnf install openldap-clients

After installation, verify it works with a simple query:

ldapsearch -x -LLL -H ldap://ldap.example.com -b "dc=example,dc=com" "(objectclass=*)"

Common flags explanation:

  • -x: Simple authentication
  • -LLL: Disable pretty-printing (machine-readable output)
  • -H: LDAP server URI
  • -b: Base DN for search

For frequent use, create an ~/.ldaprc file with defaults:

BASE dc=example,dc=com
URI ldap://ldap.example.com
BINDDN cn=admin,dc=example,dc=com

If you get SSL errors, you may need to install certificates:

sudo yum install ca-certificates

For SASL authentication issues, install additional packages:

sudo yum install cyrus-sasl cyrus-sasl-gssapi

If the package isn't in your repositories, you can:

  1. Enable EPEL repository: 
    sudo yum install epel-release
  2. Compile from source: 
    wget https://www.openldap.org/software/download/OpenLDAP/openldap-release.tgz
tar xzf openldap-release.tgz
cd openldap-*
./configure --prefix=/usr/local
make depend
make
sudo make install