英文:
python subprocess stdin truncated at first space
问题
我对pOpen.communicate()有一个问题，就是我发送给子进程的字符串在第一个空格字符处截断（请记住，我使用utf-8编码为字节）。
输入文件text.txt：
this is an input string
我的代码：
from subprocess import Popen, PIPE
# 打开文件并将其编码为utf-8字节
fp = open('test.txt')
inputs = fp.read()
inputBytes = bytes(inputs, 'utf-8')
# 打开子程序并将字节发送到STDIN
p = Popen(['./program'], stdout=PIPE, stdin=PIPE, stderr=PIPE)
stdout_data = p.communicate(input=inputBytes)
# 打印子进程的STDOUT，将打印给定的内容
out = str(stdout_data).split('\n')
for frame in out:
print(frame)
我的预期输出：
(b'this is an input string', b'')
我得到的输出：
(b'this', b'')
我是否使用了错误的编码格式？子程序是一个使用scanf监听pOpen.communicate()数据的Go应用程序。
package main
import "fmt"
func main() {
var inputs string
fmt.Print("")
fmt.Scanf("%s", &inputs)
fmt.Println(inputs)
}
英文:
I have an issue with pOpen.communicate() where the string I send to the subprocess truncates at the first occurrence of a space character I am sending to STDIN (keep in mind I am encoding to bytes using encoding utf-8)
Input file text.txt
this is an input string
My code
from subprocess import Popen, PIPE
# open file and encode to utf-8 bytes
fp = open('test.txt')
inputs = fp.read()
inputBytes = bytes(inputs, 'utf-8')
# open subprogram and send the bytes to STDIN
p = Popen(['./program'], stdout=PIPE, stdin=PIPE, stderr=PIPE)
stdout_data = p.communicate(input=inputBytes)
# print STDOUT of subprocess, will print what was given
out = str(stdout_data).split('\\n')
for frame in out:
print(frame)
my expected output:
(b'this is an input string', b'')
what I got:
(b'this', b'')
am I using the wrong encoding format? The subprogram is a go application that uses scanf to listen to pOpen.communicate() data
package main
import "fmt"
func main() {
var inputs string
fmt.Print("")
fmt.Scanf("%s", &inputs)
fmt.Println(inputs)
}
答案1
得分: 1
Go的fmt.Scanf基于C的scanf；%s会跳过前导空格，然后读取下一个单词直到第一个空格。这可能不是你想要的。
根据文档，更加精确的解释是：
由动词处理的输入隐式以空格分隔：除了
%c之外的每个动词的实现都会从剩余输入中丢弃前导空格，而%s动词（以及读入字符串的%v）会在第一个空格或换行符处停止消耗输入。(https://pkg.go.dev/fmt)
英文:
Go's fmt.Scanf is based on C's scanf; %s skips leading spaces and then reads the next word up to the first space. That's probably not what you wanted.
From the docs, a bit more precise:
> Input processed by verbs is implicitly space-delimited: the implementation of every verb except %c starts by discarding leading spaces from the remaining input, and the %s verb (and %v reading into a string) stops consuming input at the first space or newline character. (https://pkg.go.dev/fmt)
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