和awk

和awk

一般网页上发布的代码都是带有行号的,当我把代码复制粘贴到文本编辑器中时(虽然有些文本编辑器会自动去掉行号,但有时候还是不行),去掉行号是一件很麻烦的事情。

必须有一些 sed、awk 或其他 linux 解析工具来处理它。

假设我有下面的代码,如何使用上述工具安全地删除行号?

   1 /*
   2  * Beep using pcm
   3  *
   4  * Copyright (c) by Takashi Iwai <[email protected]>
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  */
  20 
  21 #include <asm/io.h>
  22 #include <asm/irq.h>
  23 #include <linux/init.h>
  24 #include <linux/slab.h>
  25 #include <linux/input.h>
  26 #include <linux/pci.h>
  27 #include <linux/dma-mapping.h>
  28 #include <sound/core.h>
  29 #include <sound/control.h>
  30 #include "pmac.h"
  31 
  32 struct pmac_beep {
  33         int running;            /* boolean */
  34         int volume;             /* mixer volume: 0-100 */
  35         int volume_play;        /* currently playing volume */
  36         int hz;
  37         int nsamples;
  38         short *buf;             /* allocated wave buffer */
  39         dma_addr_t addr;        /* physical address of buffer */
  40         struct input_dev *dev;
  41 };
  42 
  43 /*
  44  * stop beep if running
  45  */
  46 void snd_pmac_beep_stop(struct snd_pmac *chip)
  47 {
  48         struct pmac_beep *beep = chip->beep;
  49         if (beep && beep->running) {
  50                 beep->running = 0;
  51                 snd_pmac_beep_dma_stop(chip);
  52         }
  53 }
  54 
  55 /*
  56  * Stuff for outputting a beep.  The values range from -327 to +327
  57  * so we can multiply by an amplitude in the range 0..100 to get a
  58  * signed short value to put in the output buffer.
  59  */
  60 static short beep_wform[256] = {
  61         0,      40,     79,     117,    153,    187,    218,    245,
  62         269,    288,    304,    316,    323,    327,    327,    324,
  63         318,    310,    299,    288,    275,    262,    249,    236,
  64         224,    213,    204,    196,    190,    186,    183,    182,
  65         182,    183,    186,    189,    192,    196,    200,    203,
  66         206,    208,    209,    209,    209,    207,    204,    201,
  67         197,    193,    188,    183,    179,    174,    170,    166,
  68         163,    161,    160,    159,    159,    160,    161,    162,
  69         164,    166,    168,    169,    171,    171,    171,    170,
  70         169,    167,    163,    159,    155,    150,    144,    139,
  71         133,    128,    122,    117,    113,    110,    107,    105,
  72         103,    103,    103,    103,    104,    104,    105,    105,
  73         105,    103,    101,    97,     92,     86,     78,     68,
  74         58,     45,     32,     18,     3,      -11,    -26,    -41,
  75         -55,    -68,    -79,    -88,    -95,    -100,   -102,   -102,
  76         -99,    -93,    -85,    -75,    -62,    -48,    -33,    -16,
  77         0,      16,     33,     48,     62,     75,     85,     93,
  78         99,     102,    102,    100,    95,     88,     79,     68,
  79         55,     41,     26,     11,     -3,     -18,    -32,    -45,
  80         -58,    -68,    -78,    -86,    -92,    -97,    -101,   -103,
  81         -105,   -105,   -105,   -104,   -104,   -103,   -103,   -103,
  82         -103,   -105,   -107,   -110,   -113,   -117,   -122,   -128,
  83         -133,   -139,   -144,   -150,   -155,   -159,   -163,   -167,
  84         -169,   -170,   -171,   -171,   -171,   -169,   -168,   -166,
  85         -164,   -162,   -161,   -160,   -159,   -159,   -160,   -161,
  86         -163,   -166,   -170,   -174,   -179,   -183,   -188,   -193,
  87         -197,   -201,   -204,   -207,   -209,   -209,   -209,   -208,
  88         -206,   -203,   -200,   -196,   -192,   -189,   -186,   -183,
  89         -182,   -182,   -183,   -186,   -190,   -196,   -204,   -213,
  90         -224,   -236,   -249,   -262,   -275,   -288,   -299,   -310,
  91         -318,   -324,   -327,   -327,   -323,   -316,   -304,   -288,
  92         -269,   -245,   -218,   -187,   -153,   -117,   -79,    -40,
  93 };
  94 
  95 #define BEEP_SRATE      22050   /* 22050 Hz sample rate */
  96 #define BEEP_BUFLEN     512
  97 #define BEEP_VOLUME     15      /* 0 - 100 */
  98 
  99 static int snd_pmac_beep_event(struct input_dev *dev, unsigned int type,
 100                                unsigned int code, int hz)
 101 {
 102         struct snd_pmac *chip;
 103         struct pmac_beep *beep;
 104         unsigned long flags;
 105         int beep_speed = 0;
 106         int srate;
 107         int period, ncycles, nsamples;
 108         int i, j, f;
 109         short *p;
 110 
 111         if (type != EV_SND)
 112                 return -1;
 113 
 114         switch (code) {
 115         case SND_BELL: if (hz) hz = 1000;
 116         case SND_TONE: break;
 117         default: return -1;
 118         }
 119 
 120         chip = input_get_drvdata(dev);
 121         if (! chip || (beep = chip->beep) == NULL)
 122                 return -1;
 123 
 124         if (! hz) {
 125                 spin_lock_irqsave(&chip->reg_lock, flags);
 126                 if (beep->running)
 127                         snd_pmac_beep_stop(chip);
 128                 spin_unlock_irqrestore(&chip->reg_lock, flags);
 129                 return 0;
 130         }
 131 
 132         beep_speed = snd_pmac_rate_index(chip, &chip->playback, BEEP_SRATE);
 133         srate = chip->freq_table[beep_speed];
 134 
 135         if (hz <= srate / BEEP_BUFLEN || hz > srate / 2)
 136                 hz = 1000;
 137 
 138         spin_lock_irqsave(&chip->reg_lock, flags);
 139         if (chip->playback.running || chip->capture.running || beep->running) {
 140                 spin_unlock_irqrestore(&chip->reg_lock, flags);
 141                 return 0;
 142         }
 143         beep->running = 1;
 144         spin_unlock_irqrestore(&chip->reg_lock, flags);
 145 
 146         if (hz == beep->hz && beep->volume == beep->volume_play) {
 147                 nsamples = beep->nsamples;
 148         } else {
 149                 period = srate * 256 / hz;      /* fixed point */
 150                 ncycles = BEEP_BUFLEN * 256 / period;
 151                 nsamples = (period * ncycles) >> 8;
 152                 f = ncycles * 65536 / nsamples;
 153                 j = 0;
 154                 p = beep->buf;
 155                 for (i = 0; i < nsamples; ++i, p += 2) {
 156                         p[0] = p[1] = beep_wform[j >> 8] * beep->volume;
 157                         j = (j + f) & 0xffff;
 158                 }
 159                 beep->hz = hz;
 160                 beep->volume_play = beep->volume;
 161                 beep->nsamples = nsamples;
 162         }
 163 
 164         spin_lock_irqsave(&chip->reg_lock, flags);
 165         snd_pmac_beep_dma_start(chip, beep->nsamples * 4, beep->addr, beep_speed);
 166         spin_unlock_irqrestore(&chip->reg_lock, flags);
 167         return 0;
 168 }
 169 
 170 /*
 171  * beep volume mixer
 172  */
 173 
 174 static int snd_pmac_info_beep(struct snd_kcontrol *kcontrol,
 175                               struct snd_ctl_elem_info *uinfo)
 176 {
 177         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
 178         uinfo->count = 1;
 179         uinfo->value.integer.min = 0;
 180         uinfo->value.integer.max = 100;
 181         return 0;
 182 }
 183 
 184 static int snd_pmac_get_beep(struct snd_kcontrol *kcontrol,
 185                              struct snd_ctl_elem_value *ucontrol)
 186 {
 187         struct snd_pmac *chip = snd_kcontrol_chip(kcontrol);
 188         if (snd_BUG_ON(!chip->beep))
 189                 return -ENXIO;
 190         ucontrol->value.integer.value[0] = chip->beep->volume;
 191         return 0;
 192 }
 193 
 194 static int snd_pmac_put_beep(struct snd_kcontrol *kcontrol,
 195                              struct snd_ctl_elem_value *ucontrol)
 196 {
 197         struct snd_pmac *chip = snd_kcontrol_chip(kcontrol);
 198         unsigned int oval, nval;
 199         if (snd_BUG_ON(!chip->beep))
 200                 return -ENXIO;
 201         oval = chip->beep->volume;
 202         nval = ucontrol->value.integer.value[0];
 203         if (nval > 100)
 204                 return -EINVAL;
 205         chip->beep->volume = nval;
 206         return oval != chip->beep->volume;
 207 }
 208 
 209 static struct snd_kcontrol_new snd_pmac_beep_mixer = {
 210         .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 211         .name = "Beep Playback Volume",
 212         .info = snd_pmac_info_beep,
 213         .get = snd_pmac_get_beep,
 214         .put = snd_pmac_put_beep,
 215 };
 216 
 217 /* Initialize beep stuff */
 218 int __devinit snd_pmac_attach_beep(struct snd_pmac *chip)
 219 {
 220         struct pmac_beep *beep;
 221         struct input_dev *input_dev;
 222         struct snd_kcontrol *beep_ctl;
 223         void *dmabuf;
 224         int err = -ENOMEM;
 225 
 226         beep = kzalloc(sizeof(*beep), GFP_KERNEL);
 227         if (! beep)
 228                 return -ENOMEM;
 229         dmabuf = dma_alloc_coherent(&chip->pdev->dev, BEEP_BUFLEN * 4,
 230                                     &beep->addr, GFP_KERNEL);
 231         input_dev = input_allocate_device();
 232         if (! dmabuf || ! input_dev)
 233                 goto fail1;
 234 
 235         /* FIXME: set more better values */
 236         input_dev->name = "PowerMac Beep";
 237         input_dev->phys = "powermac/beep";
 238         input_dev->id.bustype = BUS_ADB;
 239         input_dev->id.vendor = 0x001f;
 240         input_dev->id.product = 0x0001;
 241         input_dev->id.version = 0x0100;
 242 
 243         input_dev->evbit[0] = BIT_MASK(EV_SND);
 244         input_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);
 245         input_dev->event = snd_pmac_beep_event;
 246         input_dev->dev.parent = &chip->pdev->dev;
 247         input_set_drvdata(input_dev, chip);
 248 
 249         beep->dev = input_dev;
 250         beep->buf = dmabuf;
 251         beep->volume = BEEP_VOLUME;
 252         beep->running = 0;
 253 
 254         beep_ctl = snd_ctl_new1(&snd_pmac_beep_mixer, chip);
 255         err = snd_ctl_add(chip->card, beep_ctl);
 256         if (err < 0)
 257                 goto fail1;
 258 
 259         chip->beep = beep;
 260 
 261         err = input_register_device(beep->dev);
 262         if (err)
 263                 goto fail2;
 264  
 265         return 0;
 266  
 267  fail2: snd_ctl_remove(chip->card, beep_ctl);
 268  fail1: input_free_device(input_dev);
 269         if (dmabuf)
 270                 dma_free_coherent(&chip->pdev->dev, BEEP_BUFLEN * 4,
 271                                   dmabuf, beep->addr);
 272         kfree(beep);
 273         return err;
 274 }
 275 
 276 void snd_pmac_detach_beep(struct snd_pmac *chip)
 277 {
 278         if (chip->beep) {
 279                 input_unregister_device(chip->beep->dev);
 280                 dma_free_coherent(&chip->pdev->dev, BEEP_BUFLEN * 4,
 281                                   chip->beep->buf, chip->beep->addr);
 282                 kfree(chip->beep);
 283                 chip->beep = NULL;
 284         }
 285 }
 286 

答案1

awk

awk '{$1="";print $0}' FileName > NewFileName

解释:

  • awk将输入/文件拆分为字段,默认分隔符为空格。
  • $1=""表示“将第一个字段设置为”无。文本中的第一个字段始终是行号,因此我们实际上是删除了行号。
  • print $0表示“打印所有字段”,因此我们打印所有字段,但第一个字段现在是空的,不会被打印。

awk这会弄乱代码格式。参见此答案了解更多信息如何保存它。


sed

sed 's/^ *[0-9]\+.//g' FileName > NewFileName

解释:

  • sed 's/<replace this>/<with this>/g'
  • ^ *[0-9]\+.意思是:从行首匹配(^),然后匹配零个或多个空格(*),然后匹配 0 到 9 之间的数字([0-9]),匹配多个数字(\+),然后匹配任意单个字符(.)。
  • 之间没有任何内容//,因此我们基本上是用空字符替换刚刚匹配的内容,从而有效地将其删除。

归功于karel 的回答用于sed命令。


cut(和sed

sed 's/^ *//g' FileName | cut -d' ' -f2- > NewFileName

解释:

  • sed 's/^ *//g',其中^ *表示:从行首开始匹配(^),然后匹配零个或多个空格(*)。然后我们将匹配的内容替换为空,以将其删除。此sed部分用于删除文件中的任何前导空格。
  • cut也是一个文本处理程序,它将输入分成多个字段(使用默认分隔符tab)。
  • -d' '将分隔符设置为空格,因此现在第一个字段是我们的数字。
  • -f2-表示从第二个字段开始打印(最后一个连字符-表示“从现在开始”)。

答案2

从终端运行:

sed 's/ *[0-9]*.//' script > script-no-line-numbers

答案3

如果您想要一种在文本编辑器中有效的方法,那么您可以使用组合键ctrlx+ r+k在 emacs 中剪切矩形文本区域。

答案4

在一些文本编辑器中吉尼或者(Windows 中仅支持 Notepad++)也可以轻松完成。只需按住 CTRL+ALT,然后按住鼠标左键单击,在编号区域周围绘制一个矩形

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