该文件有数百万行，以2个行块排列，每个块中的第1行是标题，标有>，后跟两行字母字符。
在linux和/或bash中，如何将文件拆分成较小的文件，保留2block结构？理想情况下，根据输出文件的数量或每个较小文件的块数，可以灵活地输出多少？
简短的例子：
>k99_12
CCTTCTTCAATGCCAATACCCTCGAAGAATTGCACCGCCTCGAACAAACCACATGACACACCCACCGTCACTGGCTGACATTGCCGCACAACTTGAAGCCTATGACCCGCAGGCACTACCTGCCAATGAGGTCTTGAATTTTCTGGATCACTTGGTGACGCCAGTGCACGACTCAGAATCAGTCGACATCTTTGCAGCATTGGGCAGAGTCACTGCGCAA
>k99_27
ATCCAAGCCAGAGAATATGCCTACCCGCATCGCACCGCGATCTCGCAAATGTCGTGTAATCGCGCGGGTATCAACACCCTGAATGCCAATGATTCCTTGCTCAATCAATTCCGCCTCAAGATCATTTTGTGCGCGCCAATTTGATGTCAAAGAGGATGGGTTTCTAACAACAAACCCTGCCACCCAAATCTTTGATGACTCATTATCTAA
>k99_31
CCATTGCGCAAACGGACTGCCGGACACCAAGTGCACCTCGTGCGACAGACCATACTGGTCGTCATAAGAGAGTTCAGGGTTTTCGCGGTGGTCGGCCATGCCGTCCACATTGTGCACCTGCTGGTGCAGCGAACCGCCCATGGCCACATTGATTTCCTGGAAGCCACGGCAAATCCCCAGCAGGGGCACACCCTGCGCGACGCAGGCGCGTACCAAGGGCAAGGTCAGGCTGTCGCGGTGCGGATCCAGCGGCAGACGCGGA
>k99_35
AAAATTGAGTTTGAAGGAATTTCGCATTTCATCAAAAATCAACACGACGAGAGTGGTTCAACAACTATAAAACGTTGGGCAAAGGAATTTATGGACGAAATAAATTGTCCTGTTTGCGAAGGTTCACGATTAAAAAAAGAAGCTTTATTTTTCAAAATTAATGGAAAAAACATCACTGAATTATGCAATATGGATATTTCGGATGTCACGGCTTGGTTTTTGGAATTGAACACCCATTTATCAGATAAACAAAAGACTATAGCGACGGAGGTTATCAAGGAAATAAAAGATCGATTGGCCTTTTTAATGAATGTAGGTTTGGATTATTT
>k99_40
GAGGCCGGCGAAGGCGCGGTGATCGACGAGGAGGACGACGACGCTGGCGCGGGCGAGCGCGTCGGCGAGGGAAACGAGTTCCGCCCTGCCCTGCAGCGCTTTCGGCAAGGCGGTCACGTGCGGCTCGACGGCCAGGACCTTCAGGCCGGCGTCGGCGAGGTGCGCGGCGATCTCGACGGCGGGAGATTCACGGAGGTCGTCGACGTTCGCCTTGAAGGCGAGGCCGAGGCAGGCGACGGCGGCGCCAGAA
>k99_42
AGACCAAATCGCACGGCTAGCAGGATCAAAACGCAAGATGCGCGGGTCTCTTACTTCATCGCGCAGAGTAGGGCGCATCAGCGCGACTTTTTCGCGCACGTCATCGGCGCCTTTGCGGCCGTCTATGTTGAGGTCAAACTCAACCACCACCACCGACACGCCTTCATAACTGCGAGATGTGAGGGCATTGATACCGGCAATGGAATTGACTGCTTCTTCCACTTTTTTAGTCACCTCGCTCTCGACAATTTCAGGAGAGGCGCCTGGATATTCGGTGCTCACGACAACGACGGGCAAATCAATATTAGGAAACTGGTCGATCTTGAGGCGCTGATAAGAGAACAAGCCCAGCACCACAAAGGCAAGCATCACCATCGTTGCGAAGACGGGGTTTTTGAGGCTGACTTTGGTGA
>k99_75
AAAGGTAGCATTGAAGATTATACGCAGTTGTTTCAGGCAGCAGCACAAATTGCGAATGAATCGGCACATATGCAACTCGATATAGATGTCGAGGGATTCAACGAATTTGCTACGGCGGCGGACGACCTCAGTAAGTTATTCACTGGTTTCATTTTGAAGTTGGAGAATGTGAGTATCATCGACGATACTGTATTTTTGACTGCGGTGGCAAATGCTCTCTCGAAGATAAGCAATTTGTCGAAAGTGTTTGGTAAGTTCAAAGAAACTATATTGGGCACTTCGACAATTCGTTTGCCCAAATCCGCACATGATGCATCGGTTATACTGAAAGATGTGGTTGGGCAAATCAATTGTGCAATGACGTATATAAACCATTTTGTCGATTCGAGTGTTCCCGCACCAAGTGTTGCGGAATTATCGAAAGAAGAGAAGAATATAATCGACGCTGCGGTGACAACCATTCACAATTGGAATACATTGTGTGACCAAGGAGTTAGTATTGCCATGTCAAGCGACCCAGATATTCAATTTGTTAGTAATGCGAATCAATCGCT
>k99_76
TCGTAAGCTAACTAAATCAACTGAACAATCTATCACCAATAGTATGTAATCAGAAATCAACTTAAATCTCATATATTAATGAAAGTTTTATCAATTGTTGGAACAAGGCCGGAAATAATTAAGTTATCAAGAGTGTTTCATGAACTTGAAAAATATACTGAACACATTTTAGTACATACAGGTCAAAACTTTGATTATGAACTAAATGAAATATTTTTCAATGATCTTAAAATTAAGAAACCTGATTTTTTTTTAAATGTTGTTGGCGAATCTTTAGCTGATACTATTGCAAACATAATTTCCAAATCCGATAAAGTTCTAGAAAAAATAAAACCA
>k99_79
GATGTACTGGTACTCGTTGTAGGTCGTCGTCTTGCTACCTCTGCTGCTGTCGTTCGTGGCCTCGTTGCGGTGGTCGTAGTTGTTGTGGTCGCTCTCGCAGGCCCGCCGCTCAGAGCTTGGAACGAGTTCTTGGAGACGAAGTCTCCCAGCGTTGCGCCGCGAGGCGTCGGGCGAGGTCGAGCTGCGACCTTCGCCTGGACAAAGCCGTCCTGGACCAGAGAGATGTCCATCCGCTGCGGCGGCCCCTCTTCGACGCTCCTGACGGCGCCTGTCGTTGGCCTCTGCGGGCAGGCTCGGGAGGAGTGACCGGTCTTTTTGCAGATCCAGCACTTCCGGAGCTCCCGTGCGACCTCAGGCAGGGGGCACTTGATGGCGGCGTGCGACTCGCC
>k99_83
CCCGAACACAATCGCTTTAGTCGAGCGGGAAACGCGGTGGGATTATGCGGACCCAGCCTTTACGAACGGGATCGCGGAAGACTTCTCCATCGACCAGTCTACTCACTCGCTCTTCGGCGCCTCGAAGGTTGCCGCCGACGTTTTGGTGCAGGAATACGGCCGCTATTTTGGAATGCCTACTTGCGTGCTGCGCGGCGGCTGCCTCACCGGCCCGAATCACAGCGGCGTCCAG
>k99_90
GGCTGACGTACAAGATGCGCCGTCCGTGGTCACGCGGCACGCTGGGCGTGGTGTTCAACGCGTTGTATGCCGTCATGTTCCTGTTCACGATCACGGTGATCGCGTCGATTCTCCACTCGTTCGAGTTCAACGGGCTATCCATCTTCTTCTTCCTGTTCTTCCTGTCGCTCGTGACCTTCTTCGGCCTGAAGATTCGCAATACGCGCCGCGAGCTGATGGTGGTAGAGGCGCGCGTCGGCATCGTCGGCACGATCGCGGACATCCTGTTTCTCCCCATGATACGCGCCGGCCGCTGGGTCGCGCTCCGGGCGCCGCGGGCCATCGCCACGCGGCCGGTCCGGACCATTTCCATGATCCCGTACGGCCGAAGCACCTCGAGCAGACCGTCAATCTTGTCTTCCGTACCGGTGATCTCGATGATCAGCGAATCCACCGCCACGTCGATCACCCGCGCGCGGAACACCTCGGCGAGCTGCATGACGTGCGGCCTGGATTCCGCCGACGCGGCAAC
>k99_100
AAAATACAGGTCTTTCAATGATGAAAGAAATGGATGATGCAAAAAATCTCGTTGGAATTGATTATACGAAGCATTTTGCTGATTTGGTAGAGAAAGCAGATCCTTTTGGTTCTAAAGCAGCGTTTATGCCAATGAAAGTAATTACTGCTTTGGCTTTGTTTGGTGAAAACGGCTCAACGAAAGCATTGGAAAGCTCATTAAAAAGAGGTGGAAGTGAAGAAAATTTAAACGATCTTTATTTAAACAGAGTAGGTGAGTACAAATGGAATGGTAAAACCTGGATTAAAAATAAAGAAGTTAAAGATAAAATTATTTTACGCTTTCCATCTTCTAATGCTAAAACTGTAAATAACGCTTCTTATGAAATTTCATTTGTGAACTATGCTGGAGCAGGTTTGCCTGATGA
>k99_104
GGTTCCATACATGTAACGCCAGGAATAGTGGACAACATTTGGTGCATCAGTGCGCCACGACGAGCAAATGCCTCACGCATCATGTGCACCGCTGATAAATCACCACTGACTGCAGCAAGTGCTGCAACCTGTGACACGTTGGCAACGTTTGACGTGGCATGCGATTGGAAGTTTGTTGAAGCCTTCATGATGTCTTTCGGTCCA
>k99_108
CCGCAGCATCTGACCGAGATCGAAGGGGCGGCCGTAGGGGCGCCGGCTGCTGTGCTGGCGCGCTGGACGGCGGCGGGCATGGCGCCGGCAGTCGTCATCGGCGACGGCGCGTTGGCCTTCGAGTCCCTCCTCGCCGGAGAGGCCCGCGTGTGTGGCGCGCAGCCGCTCGCCGGGACAATCGGACGAATCGCGGCGATCCGCGCGGATCGGGGAGAAGCGGTGGAGCCACACGCCGTGCGCGCGCTGTACGTCCGGCGTTCTGACGCGGAGGTCGAGAGGGACCGTGCCCGCTGATTCGAATGGTGCGGCGCCCCTCGCGCTGACGGTCGATCTCTTGTCGTCACTCGACGAACTGGACGAGGTGATGGCGGTCGA
>k99_112
ATGTCGAGCGCCAGCATTAGCGGGCGGGCGGACAAGGATGTTGATGCGCGCTCAATCGCTTTGGTGAAAACCGGTGACGAAGAAGCCAGCGCTGGCCGCGTCGATAGCGCAATTGGCTGGTATGAAACTGCGCTCGCGGTCGACCCGCGCAACCGTGCCGCTTATGTCGCCATGGCGCGCGCCGTAAAATCCCAGGGGTTG
>k99_115
GCAGTGGATGCCATACCAGAAAAAGTCGGGATGGTGCGGCTCGAATTCGGCGGGCCCGATGGAGTAGACGGAGGTGATGTCACCGATCTTGGCGAACTTTGAGGCGAAGGTTTCAGGTGGATACCTAAGGGACGAAGAACTGAAGAGTGGGATTTTGTGTTCGCGGGCGAGGCGGACGATTTCGACGGCGTCTGTAAGAGAGCCGGCGAGGGGCTTGTCGATGAAGACGGGTTTTTTCGCGGCGAGGGTCTGGCGGAATTGTTCGAGGTGGGGGCGGCCGTCGACGCTTTCGATCAGA
>k99_117
CGTCTCTGAGCTTTTCAGCTTCCATCAACTTGGCTTTTCCTATGGCCGCACTGTCGGAAACAATCGCAATCGGCCCTAACCTGGCTCCCAAGCAAGCCATGTGCATCGCCACGTGCTCAGCGGCCCCGGACGAGATTCGATATCCCACCGGAATGGCGACCGCCATGGATCTGACACAAACCTTCCCGTCCTTTCGCCATACCGTCCGTCGCTTCGTACGTCGTCTGGTGTGGCGTCGCTGTCCTCCGTGGTGCTGTAGACGTTCTCGATGGGGTCGTCGCCCTGGAAGTACTGGAGGTGGCTGTAGTCGCGCGGGAC
>k99_121
ATGAGTACAACAGTCAGTCATAACTGCGTAAGGGGCACCTGTAAATCTAGCCAATGCATGTTCAAATTCTAGTATTTTCTCAAACATTTTCGCTCAAGTGATCTTGTTTAATTTCTCGCACTGGGCAATTTAGTAATTCTGCTATAGTATTTTTAACTGCTATTCTTTTATTATTCCAATTTCTTATTAGTATAGCACGTCGTCCAATTTCTTCCAAACTTAATTCTTCTTCGCAACCACTTTTTAATTCAGCTTCTAATGTCCAGATAGTATCATGTATTCTTTTGAGCTCATCAAAACACGTTTTAACAAGAGATAAATCGAATTGTGAAGTTTGATCTTGATACCAATTAAGTTCCTCTTGATTGCTGTGTGTCCGATCCCACTTAACTTCGGCTATGGCTAATCTATCAAATAGTTCAATTACTGGAAAGTGGTAACTCATAGATATAGTCCTTCAATTTTTTCTGGA
>k99_135
AAAAGACTGTTGGCTTCTCCCAAAAAATTTACTTAAAAAATAATATTCAGACAACAATTCTTGAAAGTGCTATGCTTTGAAAGTTGTGTTTTTTTTAATTATGGCCAAAGAAAAAACAATACACACAAAAAAAGTTTGAAACATGGCCGATTTTCGTTTTAACGTGAAAGCTGATACCACAGATTAGATATAGAATAGATAGAGGCTTCCTAAATATCAGTAGTTCCCGGTCAAAGGGGCAGGATCAAGAGGGTTGCGGGGTTTCCTCTCTTCACATTGTACATTGTACACCTTGGTTGTAATAATAGAATATGTAACACCTTGT
答案 0 :(得分：3)
将文件拆分为2个行块，使用的工具是split
split -l 2 -d file file_
原始file将每2行生成file_xx个部分。这将一下子完成。您可以将2更改为所需的行数。