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usearch_global command
Search for one (default) or a few high-identity hits to a database using the USEARCH algorithm. Alignments are global. To get more than one hit, increase -maxaccepts (see accept options).

An identity threshold must be specified using the ‑id option. If full-length, exact matches are required, then it is better to use search_exact than usearch_global with -id 1.0.

The query file may be in FASTA or FASTQ format.

A database file must be specified using the ‑db option. FASTA and .udb formats are supported. For large databases, .udb format is recommended (see makeudb_usearch command).

The ‑strand option is required for nucleotide databases.

Nucleotide, protein and translated searches are supported.

See search flowchart for overview of searching in USEARCH commands.

See also
  Output files
Accept options
  Weak hits
  Termination options
  Indexing options
  Masking options
  Alignment parameters
  Alignment heuristics


usearch -usearch_global query.fasta -db proteins.udb -id 0.8 -alnout hits.aln
usearch -usearch_global reads.fastq -db ESTs.fasta -id 0.9 -blast6out hits.b6 \
  -strand plus -maxaccepts 8 -maxrejects 256