嗨，有一个关于多进程编程的作业，当我尝试逐行读取字符时遇到问题（每行由 3 个字符和 1 个整数组成）。问题是当我使用fscanf它时它不能正常工作并且它仅在每 2 个步骤中成功读取字符。在这里你可以看到我的代码；
#include <stdio.h> /* basic I/O routines. */
#include <stdlib.h>
#include <unistd.h> /* define fork(), etc. */
#include <sys/types.h> /* define pid_t, etc. */
#include <sys/wait.h> /* define wait(), etc. */
#include <signal.h> /* define signal(), etc. */
#include <pthread.h>
#include <ctype.h>
void child_process(int);
void parent_process();
void function();
int counter=0;
int bond_number=0;
char* f_strand;
int main(int argc, char* argv[]) {
counter = atoi(argv[1]);
function();
fflush(stdout);
execl("/usr/bin/killall","killall","tail",(char *) 0);
return 0;
}
void function(){
int i,k;
pid_t child_pid[counter];
char array[counter];
char array_opst[counter];
srand ( time(NULL) );
int temp;
FILE* fptr;
fptr = fopen("sample.txt","w");
if(! (f_strand=(char*)malloc(counter*sizeof(char))) ){
printf("Error\n");
exit(1);
}
for(i=0; i<counter; i++){
temp = rand()%4;
if(temp==0){
*(f_strand+i) = 'A';
fprintf(fptr,"A\n");
}
else if(temp==1){
*(f_strand+i) = 'C';
fprintf(fptr,"C\n");
}
else if(temp==2){
*(f_strand+i) = 'T';
fprintf(fptr,"T\n");
}
else if(temp==3){
*(f_strand+i) = 'G';
fprintf(fptr,"G\n");
}
}
fclose(fptr);
for (i = 0; i < counter; i++) {
if ( (child_pid[i] = fork() ) < 0) {
perror("fork");
abort();
}
else if (child_pid[i] == 0) {
child_process(i);
exit(0);
}
}
int status;
pid_t pid;
int num=counter;
while (num > 0) {
pid = wait(&status);
//printf("Child with PID %ld exited with status 0x%x.\n", (long)pid, status);
--num; // Remove pid from the pids array.
}
parent_process();
printf("\n");
}
void child_process(int index){
int i;
char str,str1,str2;
FILE* fptr;
fptr = fopen("sample.txt","r");
fseek (fptr, 2*index, SEEK_SET);
fscanf(fptr,"%c", &str);
FILE* fptr2;
fptr2 = fopen("sample_2.txt","a");
if( str == 'A' ){
str1='T';
str2=';';
fprintf(fptr2,"%c%c%c%d\n",str,str2,str1,index);
}
else if( str == 'T' ){
str1='A';
str2=';';
fprintf(fptr2,"%c%c%c%d\n",str,str2,str1,index);
}
else if( str == 'G' ){
str1='C';
str2=':';
fprintf(fptr2,"%c%c%c%d\n",str,str2,str1,index);
}
else if( str == 'C' ){
str1='G';
str2=':';
fprintf(fptr2,"%c%c%c%d\n",str,str2,str1,index);
}
fflush(stdout);
fclose(fptr);
fclose(fptr2);
sleep(1);
}
void parent_process(void){
FILE* fptr;
fptr = fopen("sample_2.txt","r");
char str,str1,str2;
int index,i,k;
char array_opst[counter]; // second strand
char array_type[counter]; // bond type
i=0;
while( !feof(fptr) ){
if(4==fscanf(fptr,"%c%c%c%d",&str,&str1,&str2,&index)){
if(feof(fptr))
break;
printf("STR = %c\n, K = %d",str,k);
array_type[index]=str1;
array_opst[index]=str2;
printf("WHILE\n");
if(array_type[index] == ':')
bond_number=bond_number+2;
else if(array_type[index] == ';')
bond_number=bond_number+3;
}
i++;
}
fclose(fptr);
}
这是 sample2.txt 的输出
C:G5
G:C6
A;T4
C:G3
G:C7
C:G8
G:C2
A;T9
T;A1
C:G0
在它尝试从文件中parent_process()逐行读取 3 个字符和一个整数。sample2.txt但它每两行执行一次此过程。我的意思是它读取前第三第五行并继续。如果您能提供帮助，我将不胜感激。