cSvn-UI for SVN Repositories

diff --git a/csvncgi/system.c b/csvncgi/system.c
new file mode 100644
index 0000000..afab9a7
--- /dev/null
+++ b/csvncgi/system.c
@@ -0,0 +1,177 @@
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <error.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <stdarg.h>
+#include <unistd.h>
+
+#include <defs.h>
+
+#include <strbuf.h>
+#include <system.h>
+
+
+#define SYSTEM_ERRMSG_SIZE 4096
+
+void system_error( const char *fmt, ... )
+{
+  va_list arg_ptr;
+  char  buf[SYSTEM_ERRMSG_SIZE];
+  char  msg[SYSTEM_ERRMSG_SIZE];
+  char *format = "%s: %s\n";
+
+  va_start( arg_ptr, fmt );
+
+  vsnprintf( msg, SYSTEM_ERRMSG_SIZE, (const void *)fmt, arg_ptr );
+
+  va_end( arg_ptr ); /* Reset variable arguments. */
+
+  snprintf( buf, SYSTEM_ERRMSG_SIZE, format, "system", msg );
+
+  (void)write( STDERR_FILENO, buf, strlen( buf ) );
+
+  exit( 1 );
+}
+
+system_errfunc system_fatal = system_error;
+
+
+static void xexec( const char *cmd )
+{
+  char *argv[4];
+  const char *shell = getenv ("SHELL");
+
+  if( !shell ) shell = "/bin/sh";
+
+  argv[0] = (char *) shell;
+  argv[1] = (char *) "-c";
+  argv[2] = (char *) cmd;
+  argv[3] = NULL;
+
+  execv( shell, argv );
+
+  /******************************************
+    xexec() is called by child process, and
+    here child process faced to FATAL error:
+   */
+  system_fatal( "Cannot exec '%s'\n", cmd );
+}
+
+static pid_t xfork( void )
+{
+  pid_t p = fork();
+
+  if( p == (pid_t) -1 )
+  {
+    system_fatal( "Cannot %s: %s\n", "fork()", strerror( errno ) );
+  }
+
+  return p;
+}
+
+pid_t sys_exec_command( struct strbuf *sb, const char *cmd )
+{
+  int pipe_fh[2];
+
+  pid_t pid = -1;
+
+  if( sb )
+  {
+    if( pipe(pipe_fh ) == -1 )
+    {
+      system_fatal( "Cannot create pipe: %s\n", strerror( errno ) );
+    }
+  }
+
+  pid = xfork();
+
+  if( pid != 0 )
+  {
+    if( sb )
+    {
+      ssize_t ret;
+
+      close(pipe_fh[1]);
+      ret = strbuf_read( sb, pipe_fh[0], 1024 );
+      if( ret < 0 )
+        system_fatal( "Cannot read pipe: %s\n", strerror( errno ) );
+      close(pipe_fh[0]);
+    }
+
+    return pid;
+  }
+
+  if( sb )
+  {
+    dup2(pipe_fh[1], STDOUT_FILENO);
+    close(pipe_fh[1]);
+    close(pipe_fh[0]);
+  }
+
+  xexec( cmd );
+  return pid; /* only to avoid compilaton warning */
+}
+
+/*****************************************************************
+  sys_wait_command() - Wait for pid.
+
+  Return values:
+  -------------
+     0  - SUCCESS
+   >=1  - status returned by child process
+    -1  - Child terminated on signal
+    -2  - Child terminated on unknown reason
+    -3  - Cannot waitpid: waitpid() retusrs -1
+
+     Error message with SIZE length saved into *ERRMSG buffer.
+ *****************************************************************/
+int sys_wait_command( pid_t pid, struct strbuf *errmsg )
+{
+  int status;
+
+  if( pid < 0 ) return (pid_t) -1;
+
+  while( waitpid( pid, &status, 0 ) == -1 )
+    if( errno != EINTR )
+    {
+      if( errmsg ) {
+        strbuf_addf( errmsg, "PID %lu: Cannot %s", (unsigned long)pid, "waitpid" );
+      }
+      return (int) -3;
+    }
+
+  if( WIFEXITED( status ) )
+  {
+    if( WEXITSTATUS (status) )
+    {
+      if( errmsg ) {
+        strbuf_addf( errmsg, "PID %lu: Child returned status %d", (unsigned long)pid, WEXITSTATUS( status ) );
+      }
+      return (int) WEXITSTATUS( status );
+    }
+  }
+  else if( WIFSIGNALED( status ) )
+  {
+    if( errmsg ) {
+      strbuf_addf( errmsg, "PID %lu: Child terminated on signal %d", (unsigned long)pid, WTERMSIG( status ) );
+    }
+    return (int) -1;
+  }
+  else
+  {
+    if( errmsg ) {
+      strbuf_addf( errmsg, "PID %lu: Child terminated on unknown reason", (unsigned long)pid );
+    }
+    return (int) -2;
+  }
+
+  return 0;
+}