.TH ELINK 1 2017-01-24 NCBI "NCBI Entrez Direct User's Manual"
.SH NAME
elink \- look up related NCBI Entrez records
.SH SYNOPSIS
\fBelink\fP (\fBedirect\ \-link\fP)
[\|\fB\-help\fP\|]
[\|\fB\-related\fP\|]
[\|\fB\-target\fP\ \fIdbname\fP\|]
[\|\fB\-name\fP\ \fIname\fP\|]
[\|\fB\-db\fP\ \fIname\fP\|]
[\|\fB\-id\fP\ \fIID(s)\fP\|]
[\|\fB\-cmd\fP\ \fIcommand\fP\|]
[\|\fB\-mode\ ref\fP\|]
[\|\fB\-holding\fP\ \fIprovider\fP\|]
[\|\fB\-batch\fP\|]
[\|\fB\-label\fP\ \fIname\fP\|]
.SH DESCRIPTION
\fBelink\fP follows links between Entrez databases,
either extending an existing \fBedirect\fP(1) pipeline
or honoring explicit \fB\-db\fP and \fB\-id\fP options.
.SH OPTIONS
.SS Destination Database
.TP
\fB\-related\fP
Look up neighbors in the same database.
.TP
\fB\-target\fP\ \fIdbname\fP
Follow links to another database.
.TP
\fB\-name\fP\ \fIname\fP
Follow an explicit link name such as
.BR pubmed_protein_refseq .
.SS Direct Record Selection
.TP
\fB\-db\fP\ \fIname\fP
Entrez database name for immediate lookups.
.TP
\fB\-id\fP\ \fIID(s)\fP
Unique identifier(s) for immediate lookups.
.SS Advanced Control
.TP
\fB\-cmd\fP\ \fIcommand\fP
Command type (returns \fBeLinkResult\fP XML):
.RS
.PD 0
.IP \fBneighbor\fP
Neighbors or links
.IP \fBneighbor_score\fP
Neighbors with computed similarity scores
.IP \fBacheck\fP
All links available
.IP \fBncheck\fP
Existence of neighbors
.IP \fBlcheck\fP
Existence of external links (LinkOuts)
.IP \fBllinks\fP
Non-library LinkOut providers
.IP \fBllinkslib\fP
All LinkOut providers
.IP \fBprlinks\fP
Primary LinkOut provider,
or URL for single UID with \fB-mode\ ref\fP.
.PD
.RE
.TP
\fB\-mode\ ref\fP
Use LinkOut provider's web site.
.TP
\fB\-holding\fP\ \fIprovider\fP
Name of LinkOut provider.
.SS Batch Processing
.TP
\fB\-batch\fP
Bypass Entrez history mechanism.
.SS Miscellaneous Arguments
.TP
\fB\-help\fP
Print usage information.
.TP
\fB\-label\fP\ \fIname\fP
Alias for query step.
.SH SEE ALSO
.BR edirect (1),
.BR einfo (1),
.BR epost (1).