C语言 fastq文件转换为fasta文件

目前只能处理短序列，若要处理长序列，可按照https://www.cnblogs.com/mmtinfo/p/13036039.html的读取方法。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define RLEN 1024

static void getfq(char *fq, char *ofq);

int main(int argc, char *argv[]){

    if(argc!=3){
        printf("infomation:\n");
        fprintf(stderr,"\tusage: %s <fastq> <fast>\n",argv[0]);
        exit(-1);
    }
    getfq(argv[1],argv[2]);
    exit(0);
}

static void getfq(char *fq, char* ofq){

    FILE *fp1=fopen(fq,"r"); 
    FILE *fp2=fopen(ofq,"w"); 

    char fline[RLEN]; 
    char read[4][RLEN]; 
    char *r=NULL; 

    while(fp1 != NULL && fp2 != NULL){
        
        for(int i=0; i<4; i++){
            r=fgets(fline,RLEN,fp1);
            if(r != NULL){
                strcpy(read[i],fline);
            }
            else{ // EOF
                goto LoopOut;
            }
        }

        for(int i=0; i<4; i++){
            switch(i)
            {
                case 0:
                    memcpy(read[i],">",1);
                    fprintf(fp2,"%s",read[i]);
                    break;
                case 1:
                    fprintf(fp2,"%s",read[i]);
                    break;
                case 2:
                    continue;
                    break;
                case 3:
                    continue;
                    break;
                default:
                    break;
            }
        }
    }
    LoopOut:
        free(r); 
        r=NULL;
        free(fp1);
        free(fp2);

    return;
}