popen () fails when running from the windows prompt

Thomas Wolff towo@towo.net
Fri Jul 15 22:31:00 GMT 2011


Am 15.07.2011 21:22, schrieb Andy Koppe:
> On 15 July 2011 19:41, Luiz Claudio Valdetaro wrote:
>> i,
>>
>> I am planning a minimalistic installation of my application using cygwin.
>> Everything works fine, except that popen() fails when running from the
>> windows prompt.
>>
>> If I ran from the bash shell prompt of cygwin , it works fine. It is the
>> only api I use that is failing. I created a simple, test program to narrow
>> the issue,  and it also fails.
>>
>> my intention is an installation with just my app, plus the cygwin.dll, as
>> little files as possible.
>>
>> This is my test program:
>>
>> main (argc,argv)
>> int argc;
>> unsigned char *argv[];
>> {
>> FILE *f;
>> char command[80]="ls -l CGI-BIN";
>> char response[200];
>>     f = popen (command,"r");
>>     if (f == NULL) {
>>        puts ("stream error");
>>        exit (0);
>>     }
>>      while (fgets(response,199,f) != NULL) {
>>         puts (response);
>>      }
>>    fclose (f);
>> }
>>
>> The program allays fails printing "stream error"
> It's because popen() requires /bin/sh.
It works if you copy the following files plus popen itself into a 
subdirectory "bin" and include that into your PATH:
cyggcc_s-1.dll
cygiconv-2.dll
cygintl-8.dll
cygncursesw-10.dll
cygreadline7.dll
cygwin1.dll
ls.exe
sh.exe

I wonder though why all these libraries are dependencies; the program 
doesn't use curses, nor intl or iconv, and I linked it with 
-static-libgcc. Still miraculous.
------
Thomas

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