From 3bf20a04ddbdf435e20a190dc45cabb5d02c7b68 Mon Sep 17 00:00:00 2001
From: http://ftp.de.debian.org/debian/pool/main/p/procps/procps_3.2.8-8.debian.tar.gz <info@debian.org>
Date: Fri, 19 Mar 2010 21:58:46 +0100
Subject: [PATCH 37/70] path_max

===================================================================
---
 proc/readproc.c |    2 +-
 pwdx.c          |   20 ++++++++++++++++----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/proc/readproc.c b/proc/readproc.c
index 0386a63..d3e85a3 100644
--- a/proc/readproc.c
+++ b/proc/readproc.c
@@ -1036,7 +1036,7 @@ proc_data_t *readproctab2(int(*want_proc)(proc_t *buf), int(*want_task)(proc_t *
  * and filled out proc_t structure.
  */
 proc_t * get_proc_stats(pid_t pid, proc_t *p) {
-	static char path[PATH_MAX], sbuf[1024];
+	static char path[32], sbuf[1024];
 	struct stat statbuf;
 
 	sprintf(path, "/proc/%d", pid);
diff --git a/pwdx.c b/pwdx.c
index cb96a52..3e88f3c 100644
--- a/pwdx.c
+++ b/pwdx.c
@@ -35,7 +35,6 @@ static void version(void)
 
 int main(int argc, char* argv[])
 {
-     char buf[PATH_MAX+1];
      regex_t re;
      int i;
 
@@ -59,6 +58,7 @@ int main(int argc, char* argv[])
 
      for (i = 1; i < argc; i++) {
           if (regexec(&re, argv[i], 0, NULL, 0) != 0) {
+               char buf[27 + strlen (argv[i]) + 1];  // Constant 27 is the length of the error string "pwdx: ... "
                snprintf(buf, sizeof buf, "pwdx: invalid process id: %s\n", argv[i]);
                die(buf);
           }
@@ -68,9 +68,13 @@ int main(int argc, char* argv[])
 
      regfree(&re);
 
+     int alloclen = 128;
+     char *pathbuf = malloc(alloclen);
+
      for (i = 1; i < argc; i++) {
-          char * s = buf;
+          char * s;
           int len;
+          char buf[10 + strlen(argv[i]) + 1]; // Constant 10 is the length of strings "/proc/" + "/cwd" + 1
           
           // At this point, all arguments are in the form /proc/nnnn
           // or nnnn, so a simple check based on the first char is
@@ -82,14 +86,22 @@ int main(int argc, char* argv[])
 
           // buf contains /proc/nnnn/cwd symlink name on entry, the
           // target of that symlink on return
-          if ((len = readlink(buf, buf, PATH_MAX)) < 0) {
+          while ((len = readlink(buf, pathbuf, alloclen)) == alloclen) {
+               alloclen *= 2;
+               pathbuf = realloc(pathbuf, alloclen);
+          }
+
+          if (len < 0) {
                s = strerror(errno == ENOENT ? ESRCH : errno);
           } else {
-               buf[len] = 0;
+               pathbuf[len] = 0;
+               s = pathbuf;
           }
 
           printf("%s: %s\n", argv[i], s);
      }
 
+     free(pathbuf);
+
      return 0;
 }
-- 
1.7.0