2 files changed, 156 insertions, 0 deletions
diff --git a/src/posix/deps-exe/posix-cd b/src/posix/deps-exe/posix-cd
new file mode 100644
index 0000000..e7187fe
--- /dev/null
+++ b/src/posix/deps-exe/posix-cd
@@ -0,0 +1 @@
+-lskarnet
diff --git a/src/posix/posix-cd.c b/src/posix/posix-cd.c
new file mode 100644
index 0000000..8a98981
--- /dev/null
+++ b/src/posix/posix-cd.c
@@ -0,0 +1,155 @@
+/* ISC license. */
+
+#include <sys/stat.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <locale.h>
+
+#include <skalibs/bytestr.h>
+#include <skalibs/sgetopt.h>
+#include <skalibs/allreadwrite.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+#define USAGE "posix-cd [ -L | -P ] [ - | path ] [ prog... ]"
+#define dieusage() strerr_dieusage(100, USAGE)
+#define dienomem() strerr_diefu1sys(100, "stralloc_catb")
+
+int main (int argc, char const **argv, char const *const *envp)
+{
+  int phy = 0 ;
+  int dopwd = 0 ;
+  char const *where ;
+  int got = 0 ;
+  stralloc sa = STRALLOC_ZERO ;
+  PROG = "posix-cd" ;
+  setlocale(LC_ALL, "") ; /* yeah, as if */
+
+  {
+    subgetopt_t l = SUBGETOPT_ZERO ;
+    for (;;)
+    {
+      int opt = subgetopt_r(argc, argv, "LP", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'L' : phy = 0 ; break ;
+        case 'P' : phy = 1 ; break ;
+        default : dieusage() ;
+      }
+    }
+    argc -= l.ind ; argv += l.ind ;
+  }
+  if (!argc) where = getenv("HOME") ;
+  else
+  {
+    where = *argv++ ;
+    if (!strcmp(where, "-"))
+    {
+      where = getenv("OLDPWD") ;
+      dopwd = 1 ;
+    }
+  }
+  if (!where || !where[0]) dieusage() ;
+
+  if ((where[0] != '/' && (where[0] != '.')) || (where[1] && where[1] != '.'))
+  {
+    char const *cdpath = getenv("CDPATH") ;
+    if (cdpath)
+    {
+      size_t pos = 0 ;
+      size_t len = strlen(cdpath) ;
+      while (pos < len)
+      {
+        struct stat st ;
+        size_t m = byte_chr(cdpath + pos, len - pos, ':') ;
+        sa.len = 0 ;
+        if (m)
+        {
+          if (!stralloc_catb(&sa, cdpath + pos, m)) dienomem() ;
+          if (cdpath[pos + m - 1] != '/' && !stralloc_catb(&sa, "/", 1)) dienomem() ;
+        }
+        else if (!stralloc_catb(&sa, "./", 2)) dienomem() ;
+        if (!stralloc_cats(&sa, where) || !stralloc_0(&sa)) dienomem() ;
+        if (!stat(sa.s, &st) && S_ISDIR(st.st_mode))
+        {
+          got = 1 ;
+          dopwd = 1 ;
+          break ;
+        }
+        pos += m+1 ;
+      }
+    }
+  }
+
+  if (!got && (!stralloc_cats(&sa, where) || !stralloc_0(&sa))) dienomem() ;
+
+  {
+    size_t sabase = sa.len ;
+    if (sagetcwd(&sa) < 0) strerr_diefu1sys(111, "getcwd") ;
+    if (!stralloc_0(&sa)) dienomem() ;
+    if (!pathexec_env("OLDPWD", sa.s + sabase)) dienomem() ;
+    sa.len = sabase ;
+  }
+
+  if (!phy)
+  {
+    char const *x = getenv("PWD") ;
+    if (x && sa.s[0] != '/')
+    {
+      size_t len = strlen(x) ;
+      int doslash = len && x[len-1] != '/' ;
+      if (!stralloc_insertb(&sa, 0, x, len + doslash)) dienomem() ;
+      if (doslash) sa.s[len] = '/' ;
+    }
+    {
+      stralloc tmp = STRALLOC_ZERO ;
+      if (!stralloc_ready(&tmp, sa.len + 2)) dienomem() ;
+      if (!path_canonicalize(tmp.s, sa.s, 1))
+        strerr_diefu4sys(111, "canonicalize ", sa.s, ": problem with ", tmp.s) ;
+      stralloc_free(&sa) ;
+      sa = tmp ;
+    }
+    if (!pathexec_env("PWD", sa.s)) dienomem() ;
+    if (sa.len > PATH_MAX && strlen(where) < PATH_MAX && x && *x)
+    {
+      size_t len = strlen(x) ;
+      int hasslash = x[len-1] == '/' ;
+      if (!strncmp(sa.s, x, len))
+      {
+        if (hasslash || (sa.len > len && sa.s[len] == '/'))
+        {
+          sa.len -= len + !hasslash ;
+          memmove(sa.s, sa.s + len + !hasslash, sa.len) ;
+        }
+      }
+    }
+  }
+
+ /* fking finally */
+
+  if (chdir(sa.s) < 0)
+    strerr_diefu2sys(111, "chdir to ", where) ;
+
+ /* and there's still more nonsense to do afterwards! */
+
+  if (phy)
+  {
+    sa.len = 0 ;
+    if (sagetcwd(&sa) < 0) strerr_diefu1sys(111, "getcwd") ;
+    if (!stralloc_0(&sa)) dienomem() ;
+    if (!pathexec_env("PWD", sa.s)) dienomem() ;
+  }
+  
+  if (dopwd)
+  {
+    sa.s[sa.len - 1] = '\n' ;
+    if (allwrite(1, sa.s, sa.len) < sa.len)
+      strerr_diefu1sys(111, "write to stdout") ;
+  }
+
+  xpathexec0(argv) ;
+}