A Kernel Newbie's Startting Point: 09/01/2008

再说find的action，是个很有用的工具，

对于查看目录下的所有文件，普通人常用的是ls，不带任何参数的ls，碰到有子目录的情况，就cd到子目录里面，进去只为敲个ls，再又cd回来，因为当前还是主要工作目录，需要查看哪个目录时就cd到哪儿去；进阶一点的人会用ls后接目录参数，可是ls还是只能列出一个目录，对于需要同时查看多个目录的情况可以用"ls -R"，可是它只列出了文件名，没有全路径，对于下一步的最大可能是cat或调用编辑器，有了全路径才是最有用的；

试试这个： "find -ls"

一次将目录下所有文件都以ls方式列表出来，可以是递归的方式看到所有文件的"ls -l"方式的结果，并且有了全路径，可以用鼠标双击全选中，再敲中键(就是鼠标滚轮)便会粘贴出来，C-A定位光标到达行首，加上个cat或者vim，阅读或者是编辑，一切操作都是连贯的；

在Shell应用中，对/proc/sys/或/sys/下的查看常常既有列表还需要阅读变量内容，以前的做法是：

find /proc/sys/vm -type f -ls -exec cat {} \;

或者需要监视这个变量值的变化情况，加上个watch，每隔1s重读一次：

watch -n1 'find /proc/sys/vm -type f -printf "%p\t" -exec cat {} \;'

find是一个简单而强大的工具，绝不只是如名称一般只有"查找"文件的功用，它的参数有两个基本类型：

test是一个条件判断，如查按文件名查找使用"-name ..."；

action是对找到的文件的一个动作，如缺省的-print是打印全路径名，-ls是模拟ls方式列表；

缺省的action只有ls,printf等，(printf另有强大的功能)，而-exec扩展方式可以后接程序执行，如上面的-exec cat读出文件内容，

但是-exec cat实在太常用了，今日作了一个patch，在find-4.5.2上面加上-cat这个action，这样上面的监视命令就可以简化为：

find /proc/sys/vm -cat

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---
find/defs.h   |    1 +
find/parser.c |   22 ++++++++++++++++++++++
find/pred.c   |   52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
find/tree.c   |    1 +
4 files changed, 76 insertions(+)

Index: findutils-4.5.2/find/defs.h
===================================================================
--- findutils-4.5.2.orig/find/defs.h
+++ findutils-4.5.2/find/defs.h
@@ -411,6 +411,7 @@ PREDICATEFUNCTION pred_cnewer;
PREDICATEFUNCTION pred_comma;
PREDICATEFUNCTION pred_ctime;
PREDICATEFUNCTION pred_delete;
+PREDICATEFUNCTION pred_cat;
PREDICATEFUNCTION pred_empty;
PREDICATEFUNCTION pred_exec;
PREDICATEFUNCTION pred_execdir;
Index: findutils-4.5.2/find/parser.c
===================================================================
--- findutils-4.5.2.orig/find/parser.c
+++ findutils-4.5.2/find/parser.c
@@ -91,6 +91,7 @@ static boolean parse_cnewer        PARAM
static boolean parse_comma         PARAMS((const struct parser_table*, char *argv[], int *arg_ptr));
static boolean parse_daystart      PARAMS((const struct parser_table*, char *argv[], int *arg_ptr));
static boolean parse_delete        PARAMS((const struct parser_table*, char *argv[], int *arg_ptr));
+static boolean parse_cat           PARAMS((const struct parser_table*, char *argv[], int *arg_ptr));
static boolean parse_d             PARAMS((const struct parser_table*, char *argv[], int *arg_ptr));
static boolean parse_depth         PARAMS((const struct parser_table*, char *argv[], int *arg_ptr));
static boolean parse_empty         PARAMS((const struct parser_table*, char *argv[], int *arg_ptr));
@@ -253,6 +254,7 @@ static struct parser_table const parse_t
{ARG_TEST,       "ctime",                  parse_time, pred_ctime}, /* POSIX */
PARSE_POSOPT     ("daystart",              daystart),      /* GNU */
PARSE_ACTION     ("delete",                delete), /* GNU, Mac OS, FreeBSD */
+  PARSE_ACTION     ("cat",                   cat), /* GNU */
PARSE_OPTION     ("d",                     d), /* Mac OS X, FreeBSD, NetBSD, OpenBSD, but deprecated  in favour of -depth */
PARSE_OPTION     ("depth",                 depth), /* POSIX */
PARSE_TEST       ("empty",                 empty),      /* GNU */
@@ -801,6 +803,26 @@ parse_delete (const struct parser_table*
}

static boolean
+parse_cat (const struct parser_table* entry, char *argv[], int *arg_ptr)
+{
+  struct predicate *our_pred;
+  (void) argv;
+  (void) arg_ptr;
+
+  our_pred = insert_primary (entry);
+  our_pred->side_effects = our_pred->no_default_print = true;
+  our_pred->need_stat = our_pred->need_type = false;
+  our_pred->est_success_rate = 1.0f;
+  open_stdout(&our_pred->args.printf_vec);
+
+#ifdef DEBUG
+  fprintf(stderr, "%s(%s:%d) called.\n", __func__, __FILE__, __LINE__);
+#endif
+
+  return true;
+}
+
+static boolean
parse_depth (const struct parser_table* entry, char **argv, int *arg_ptr)
{
(void) entry;
Index: findutils-4.5.2/find/pred.c
===================================================================
--- findutils-4.5.2.orig/find/pred.c
+++ findutils-4.5.2/find/pred.c
@@ -445,6 +445,58 @@ pred_delete (const char *pathname, struc
}

boolean
+pred_cat (const char *pathname, struct stat *stat_buf, struct predicate *pred_ptr)
+{
+  FILE * stream = pred_ptr->args.printf_vec.stream;
+  FILE * input_stream;
+  char buf[BUFSIZ];
+  int fd;
+  size_t read_len;
+
+  (void) pred_ptr;
+  (void) stat_buf;
+
+#ifdef DEBUG
+  fprintf(stderr, "%s(%s:%d) called.\n", __func__, __FILE__, __LINE__);
+#endif
+
+  if ((fd = openat(state.cwd_dir_fd, state.rel_pathname, O_RDONLY
+#if defined O_LARGEFILE
+      |O_LARGEFILE
+#endif
+     )) <>
+    {
+      error (0, errno, "%s", safely_quote_err_filename(0, pathname));
+      state.exit_status = 1;
+      return false;
+    }
+
+  input_stream = fdopen(fd, "r");
+  if (input_stream == NULL)
+    {
+      error (0, errno, "%s", safely_quote_err_filename(0, pathname));
+      state.exit_status = 1;
+      return false;
+    }
+
+  while ((read_len = fread(buf, 1, sizeof buf, input_stream)) > 0)
+    {
+#ifdef DEBUG
+      fprintf(stderr, "%s(%s:%d): read_len = %d, stream = %p\n",
+   __func__, __FILE__, __LINE__, read_len, stream);
+#endif
+      fwrite(buf, 1, read_len, stream);
+
+      if (read_len <>
+ break;
+    }
+
+  fclose(input_stream);
+
+  return true;
+}
+
+boolean
pred_empty (const char *pathname, struct stat *stat_buf, struct predicate *pred_ptr)
{
(void) pathname;
Index: findutils-4.5.2/find/tree.c
===================================================================
--- findutils-4.5.2.orig/find/tree.c
+++ findutils-4.5.2/find/tree.c
@@ -906,6 +906,7 @@ static struct pred_cost_lookup costlooku
{ pred_comma     ,  NeedsNothing,        },
{ pred_ctime     ,  NeedsStatInfo,       },
{ pred_delete    ,  NeedsSyncDiskHit     },
+    { pred_cat       ,  NeedsNothing         },
{ pred_empty     ,  NeedsStatInfo        },
{ pred_exec      ,  NeedsEventualExec    },
{ pred_execdir   ,  NeedsEventualExec    },

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参看这个帖子来个实用的：查看文件链接，回复find命令的人是我：有人需要一些shell功能，想到了用python去写，想法不错，却没想到的是，那一段的python代码只对应了一行find命令。

Upgrade kernel to v2.6.27-rc5, x11-drivers/nvidia-drivers have not support so late kernel,

So let's upgrade it manually:

http://paste.ubuntu.com/42782/

Index: NVIDIA-Linux-x86-173.14.12-pkg0/usr/src/nv/nv-linux.h
===================================================================
--- NVIDIA-Linux-x86-173.14.12-pkg0.orig/usr/src/nv/nv-linux.h
+++ NVIDIA-Linux-x86-173.14.12-pkg0/usr/src/nv/nv-linux.h
@@ -77,6 +77,7 @@


#if !defined(KERNEL_2_4)
#include <linux/sched.h>            /* suser(), capable() replacement   */
+#include <linux/pid.h>              /* for find_pid  */
#include <linux/moduleparam.h>      /* module_param()                   */
#include <linux/smp_lock.h>         /* kernel_locked                    */
#include <asm/tlbflush.h>           /* flush_tlb(), flush_tlb_all()     */

@@ -104,7 +105,7 @@
#endif

#include <linux/spinlock.h>
-#include <asm/semaphore.h>
+#include <linux/semaphore.h>
#include <linux/completion.h>
#include <linux/highmem.h>


Index: NVIDIA-Linux-x86-173.14.12-pkg0/usr/src/nv/os-interface.c
===================================================================
--- NVIDIA-Linux-x86-173.14.12-pkg0.orig/usr/src/nv/os-interface.c
+++ NVIDIA-Linux-x86-173.14.12-pkg0/usr/src/nv/os-interface.c
@@ -704,7 +704,7 @@ RM_STATUS NV_API_CALL os_kill_process(
    U032 sig
)
{
-    return kill_proc(pid, sig, 1) ? RM_ERR_OPERATING_SYSTEM : RM_OK;
+    return kill_pid(find_vpid(pid), sig, 1) ? RM_ERR_OPERATING_SYSTEM : RM_OK;

}

/*******************************************************************************/

this patch also reflects some changes in 2.6.27:
1. asm/semaphore.h => linux/semaphore.h stands a common implementation in all arch;
2. kill_proc => kill_pid

But there's still a problem haven't been resolved, it reports license issues in modpost phase:
1. kill_pid is exported with EXPORT_SYMBOL_GPL, can be used only by GPL code;
2. nvidia.ko is licensed with "NVIDIA", not GPL;

# cd /var/tmp/portage/x11-drivers/nvidia-drivers-173.14.12/work/NVIDIA-Linux-x86-173.14.12-pkg0/usr/src/nv/

# make -C /usr/src/linux-2.6.27-rc5/ M=$PWD modules

the core functionality of nvidia.ko is hidden in nv-kernel.o, that's completely binary, there's no corespoding nv-kernel.c, results of `strings` told that the license is declared in this binary file;

the last killer approach is hexeditor! use it to hexedit the string to "GPL\0", compiling well, insmod well, all runs OK!

Hexediting is an ugly hack, hope my next machine can run toally under free operating system, no hidden binary anymore!

A Kernel Newbie's Startting Point

Tuesday, September 30, 2008

再说find action，提高终端下的工作效率

Monday, September 22, 2008

KS2008与LPC2008刚结束

Tuesday, September 02, 2008

manually upgrade x11-drivers/nvidia-drivers