os/exec: exec.Command docker run exit status 1 #14097
Description
package main
/*
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
void executeCmd(const char* cmd)
{
FILE *fp;
char buf[1024];
int readSize;
int bufSize;
bufSize = sizeof(buf) - 1;
fp = popen(cmd, "r");
if (fp != NULL)
{
while(1)
{
readSize = fread(buf, sizeof(char), bufSize, fp);
if(readSize <= 0)
{
break;
}
buf[readSize] = '\0';
printf("%s", buf);
}
pclose(fp);
}
else
printf("executeCmd popen null:%s\n",strerror(errno));
}
*/
import "C"
import (
"fmt"
"os/exec"
"unsafe"
)
func RunExecCommand() {
fmt.Println("RunExecCommand")
bs, err := exec.Command("docker", "run ubuntu:14.04 echo hello").Output()
if err != nil {
fmt.Println("docker error:", err)
} else {
text := string(bs)
fmt.Println(text)
}
}
func RunCPopen() {
fmt.Println("RunCPopen")
gostr := "docker run ubuntu:14.04 echo hello"
cstr := C.CString(gostr)
C.executeCmd(cstr)
C.free(unsafe.Pointer(cstr))
}
func main() {
RunExecCommand()
RunCPopen()
}The output is:
RunExecCommand
docker error: exit status 1
RunCPopen
hello
I expect “exec.Command("docker", "run ubuntu:14.04 echo hello").Output()" output is "hello", but it is "docker error: exit status 1". So i write c function "executeCmd" to test it, and it works fine.
My question is why exec.Command is incorrect?