Find Web Server Redirect Rules

Browsers report a redirect loop or HTTP/HTTPS behavior disagrees, and you need to find redirect rules before changing DNS or TLS.

Command

grep -RInE 'return[[:space:]]+30[18]|rewrite[[:space:]]|Redirect[[:space:]]|RewriteRule|RewriteCond' fixtures/nginx fixtures/apache

Before you run this

System impact: Read-only. Can create load on large logs, directories, filesystems, or process tables.

When not to use it: Do not assume every rewrite causes a client-visible redirect. Inspect status codes, conditions, and the matching server block before editing.

Expected output

Config paths and redirect or rewrite lines, enough to identify which file needs careful review.

System impact

Read-only, can be slow. Nothing changes. The command searches config text for common redirect and rewrite directives.

Scope this to the smallest useful path or service on busy systems.

Recovery / rollback: no state is changed.

When to use it

Use when browsers report too many redirects, HTTP redirects to the wrong place, or HTTPS redirects back to HTTP.

When not to use it

Do not assume every rewrite causes a client-visible redirect. Inspect status codes, conditions, and the matching server block before editing.

Watch this command run

Command transcript

This sanitized transcript shows the commands and output shape without exposing host details.

demo@lab:~$

$ grep -RInE 'return[[:space:]]+30[18]|rewrite[[:space:]]|Redirect[[:space:]]|RewriteRule|RewriteCond' sample-files/nginx sample-files/apache

sample-files/nginx/sites-enabled/example.conf:4:    return 301 https://example.com$request_uri;
sample-files/apache/sites-enabled/example.conf:5:    Redirect permanent / https://example.com/
sample-files/apache/sites-available/example.conf:5:    Redirect permanent / https://example.com/

$ grep -RInE 'server_name|ServerName' sample-files/nginx sample-files/apache

sample-files/nginx/sites-enabled/example.conf:3:    server_name example.com example.com;
sample-files/nginx/sites-enabled/example.conf:8:    server_name example.com example.com;
sample-files/nginx/conf.d/admin.conf:3:    server_name admin.internal;
sample-files/apache/sites-enabled/app.conf:2:    ServerName example.com
sample-files/apache/sites-enabled/example.conf:2:    ServerName example.com
sample-files/apache/sites-available/app.conf:2:    ServerName example.com
sample-files/apache/sites-available/example.conf:2:    ServerName example.com

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