我需要运行 Linux CLI 命令并从 C 获取其标准输出。
我可以使用 pipeline() 创建一个管道，然后 fork/exec，在调用 exec() 之前将子级的标准输出描述符重定向到管道，并从父级中的管道读取。另外我还得伺候孩子。
是否有一个简单的调用来执行 fork + 重定向 + exec + wait，就像 system() 执行 fork + exec + wait 一样，只有 system() 不执行重定向。
有popen()，它执行fork+redirect+exec，但不执行等待，所以我无法获得退出状态。
是这个吗？
NAME
popen, pclose - process I/O
SYNOPSIS
#include <stdio.h>
FILE *popen(const char *command, const char *type);
int pclose(FILE *stream);
DESCRIPTION
The popen() function opens a process by creating a pipe, forking,
and invoking the shell. Since a pipe is by definition unidirectional, the
type argument may specify only reading or writing, not both; the resulting
stream is correspondingly read-only or write-only.
The command argument is a pointer to a null-terminated string
containing a shell command line. This command is passed to /bin/sh
using the -c flag; interpretation, if any, is performed by the shell.
The type argument is a pointer to a null-terminated string which must be
either ‘r’ for reading or ‘w’ for writing.
The return value from popen() is a normal standard I/O stream in
all respects save that it must be closed with pclose() rather than fclose().
Writing to such a stream writes to the standard input of the command; the
command’s standard output is the same as that of the process that called
popen(), unless this is altered by the command itself. Conversely, reading
from a ‘‘popened’’ stream reads the command’s standard output, and the
command’s standard input is the same as that of the process that called
popen().
Note that output popen() streams are fully buffered by default.
The pclose() function waits for the associated process to terminate
and returns the exit status of the command as returned by wait4().
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