Fastq_to_fasta allows to convert fastq files to fasta files. You can specify whether you want to rename sequence identifiers to numbers and keep sequences with unknown (N) nucleotides
Parent program: fastx_toolkit
FASTX-Toolkit is a software package for preprocessing output data produced by Next-Generation sequencing machines in FASTA and FASTQ format before the main processing (assembling, mapping etc.). FASTQ to FASTA conversion, statistics calculation, file customization, quality-based preprocessing, trimming and etc. can be provided.