NAME

       elink - look up related NCBI Entrez records

SYNOPSIS

       elink   (edirect -link)   [-help]   [-related]   [-target dbname]   [-name name]  [-db name]  [-id ID(s)]
       [-input filename] [-cmd command] [-holding provider] [-cited] [-cites] [-batch]

DESCRIPTION

       elink follows links between Entrez  databases,  either  extending  an  existing  edirect(1)  pipeline  or
       honoring explicit -db and -id (or -input) options.

       It  has  two  implementations:  a  shell  implementation  on  top  of  nquire(1)  and  a  historical Perl
       implementation that amounts to running  edirect  -link,  enabled  by  setting  the  environment  variable
       USE_NEW_EDIRECT   to  a  false  value  as  described  in  the  ENVIRONMENT  section.   Some  options  are
       implementation-specific, as detailed below.

OPTIONS

   Destination Database
       -related
              Look up neighbors in the same database.

       -target dbname
              Follow links to another database.

       -name name
              Follow  an  explicit  link  name  such   as   pubmed_protein_refseq,   pubmed_pubmed_citedin,   or
              pubmed_pubmed_refs.

   Direct Record Selection
       -db name
              Entrez database name for immediate lookups.

       -id ID(s)
              Unique identifier(s) for immediate lookups.

       -input filename (shell implementation only)
              Read identifer(s) from file instead of standard input.

   Advanced Control
       -cmd command
              Command type (returns eLinkResult XML):
              history (shell implementation only)
                     Save results in Entrez history server
              neighbor
                     Neighbors or links
              neighbor_score
                     Neighbors with computed similarity scores
              acheck All links available
              ncheck Existence of neighbors
              lcheck Existence of external links (LinkOuts)
              llinks Non-library LinkOut providers
              llinkslib (Perl) or llibs (shell)
                     All LinkOut providers
              prlinks
                     Primary LinkOut provider.

       -holding provider (Perl implementation only)
              Name of LinkOut provider.

   PubMed Citation Lookup
       -cited References to this paper.

       -cites Publication reference list.

   Batch Processing
       -batch (Perl implementation only)
              Bypass Entrez history mechanism.

   Miscellaneous Arguments
       -help  Print usage information.

ENVIRONMENT

       USE_NEW_EDIRECT
              Whether  to  use the current shell implementation or revert to the historical Perl implementation.
              Canonical  true  values  are  1,  on  (case-insensitive),   true   (case-insensitive),   and   yes
              (case-insensitive);    canonical    false    values   are   0,   off   (case-insensitive),   false
              (case-insensitive), and no (case-insensitive).

SEE ALSO

       edirect(1), einfo(1), epost(1), nquire(1), protein-neighbors(1).

NCBI                                               2021-03-07                                           ELINK(1)