[hackers] [ubase] Add pwdx(1) || Mattias Andrée

[git]

commit f26a1449bfa18a6fbbe263f084df4e490772e9d3
Author:     Mattias Andrée <maand...@kth.se>
AuthorDate: Sat Mar 26 12:58:37 2016 +0100
Commit:     sin <s...@2f30.org>
CommitDate: Wed Apr 20 23:08:51 2016 +0100

    Add pwdx(1)
    
    Signed-off-by: Mattias Andrée <maand...@kth.se>

diff --git a/Makefile b/Makefile
index 59616a4..453607c 100644
--- a/Makefile
+++ b/Makefile
@@ -70,6 +70,7 @@ BIN = \
        pidof             \
        pivot_root        \
        ps                \
+       pwdx              \
        readahead         \
        respawn           \
        rmmod             \
@@ -106,6 +107,7 @@ MAN1 = \
        passwd.1            \
        pidof.1             \
        ps.1                \
+       pwdx.1              \
        respawn.1           \
        stat.1              \
        su.1                \
diff --git a/TODO b/TODO
index 3e89e68..21f5c20 100644
--- a/TODO
+++ b/TODO
@@ -19,7 +19,6 @@ mkswap [-L]
 partprobe
 pmap
 ps (support for more options)
-pwdx
 rfkill
 rmgroup
 rmuser
diff --git a/pwdx.1 b/pwdx.1
new file mode 100644
index 0000000..aadb6b4
--- /dev/null
+++ b/pwdx.1
@@ -0,0 +1,13 @@
+.Dd March 26, 2015
+.Dt PWDX 1
+.Os ubase
+.Sh NAME
+.Nm pwdx
+.Nd print working directory of other processes
+.Sh SYNOPSIS
+.Nm
+.Ar pid...
+.Sh DESCRIPTION
+.Nm
+Prints the current working directory for each
+.Ar pid .
diff --git a/pwdx.c b/pwdx.c
new file mode 100644
index 0000000..57adc72
--- /dev/null
+++ b/pwdx.c
@@ -0,0 +1,51 @@
+/* See LICENSE file for copyright and license details. */
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "util.h"
+
+static void
+usage(void)
+{
+       eprintf("usage: %s pid...\n", argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+       int ret = 0;
+       char path[PATH_MAX];
+       char target[PATH_MAX + sizeof(" (deleted)")];
+       ssize_t n;
+
+       ARGBEGIN {
+       default:
+               usage();
+       } ARGEND;
+
+       if (argc == 0)
+               usage();
+
+       for (; argc > 0; argc--, argv++) {
+               n = snprintf(path, sizeof(path), "/proc/%s/cwd", *argv);
+               if (n < 0 || n > sizeof(path)) {
+                       errno = ESRCH;
+               } else {
+                       n = readlink(path, target, sizeof(target) - 1);
+                       if (n >= 0) {
+                               target[n] = '\0';
+                               printf("%s: %s\n", *argv, target);
+                               continue;
+                       }
+               }
+               if (errno == ENOENT)
+                       errno = ESRCH;
+               weprintf("%s:", *argv);
+               ret = 1;
+       }
+
+       return ret;
+}