On Wednesday 17 May 2017 05:08 PM, Rajula Vineet wrote:
Hi all,
I am working on improving pharo command line as a part of my GSoC project. I
have been looking at different current working directory implementations. I
have written a blog post
<https://vineetreddy.wordpress.com/2017/05/17/pwd-vs-getcwd/> on it. It
would be of great help, if you can take a look and give your feedback.
Vineet,
Don't depend on getenv(). It is the parent (e.g. sh) which sets PWD to
the current working directory before exec-ing your program. When a child
process is spawned, the parent can decide not to pass this down to
child. e.g.
$ env -u PWD ./try
Or, if the child process changes its working directory using chdir(),
PWD will not change. e.g.
--- try.c ---
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
int main(int argc, char *argv[])
{
char cwd[PATH_MAX];
for(;;) {
if (getcwd(cwd, sizeof(cwd)) != NULL)
printf("getcwd: %s\n", cwd);
else
perror("getcwd() error");
printf("PWD: %s\n", getenv("PWD"));
if (argv[1]) {
printf("chdir %s\n", argv[1]);
chdir(argv[1]);
argc--; argv++;
}
else
break;
}
return 0;
}
-------
Regards .. Subbu
