Troubleshooting

Most of these come down to network reality or how CSDN serves its data, not a bug.

A command exits 4 (walled)

CSDN itself is open, with no key and no signing, so the only thing that exits 4 is the anti-bot edge. It scores each caller and, when it decides a request is not a real browser, it fronts one of three blocks:

• a 521 status,
• a 403 cdn_cgi_bs_bot challenge page,
• or an HTML challenge shell in place of the page.

The client already sends a full Chrome header set and the Referer each surface expects, which is what keeps a normal request out of the challenge. When the edge walls anyway, csdn exits 4 (needs auth) with a hint that the surface needs a residential session, rather than pretending it found nothing or printing the challenge page as data. A 521 is retried; a 403 maps straight to walled, because the edge engages it per surface after repeated calls from one address.

What this looks like in practice: from a datacenter IP, hot, search, article, user, and posts all returned rich real records, while comments was the one surface the wall held shut (a sticky 403). From a normal residential IP, all six return real data. If you are walled, run the command from a residential IP or a warm browser session, or slow down with --rate.

A genuinely empty result (exit 3) versus a wall (exit 4)

csdn distinguishes the two. A successful request that simply found no items exits 3 (no results). A blocked request, where the edge returned a challenge, exits 4 (needs auth). A specific id or username that does not exist exits 6 (not found). Check the exit code in scripts to tell them apart.

article rejects a bare numeric id

CSDN article URLs carry the author username in the path, so an article cannot be addressed by its numeric id alone. Pass a full article URL or the username/id shorthand (for example csdn article LOVEmy134611/161870903). The comments command is different: its list is keyed only by the article id, so a bare numeric id is fine there.

Requests start failing or returning 429

CSDN rate-limits like any public site. csdn already paces requests and retries the transient failures, but a hard limit still means backing off. Raise the delay between requests with --rate (for example --rate 1s) and retry later. A burst of 429 or 5xx responses is the site asking you to slow down, not a defect. A 429 after retries exits 5 (rate limited).

Seeing exactly what a surface returned

When a command exits 4 and you want to see the body for yourself, use the raw escape hatch:

csdn raw https://blog.csdn.net/LOVEmy134611/article/details/161870903

It prints the page or endpoint body untouched, including a challenge shell when walled, so you can confirm the wall rather than guess. Add -v for per-request detail on any command.

The binary is not on your PATH

go install puts the binary in $(go env GOPATH)/bin (usually ~/go/bin), and a release archive leaves it wherever you unpacked it. If your shell cannot find csdn, add that directory to your PATH. See installation.