linux_sed&tr_将所有空白符(空格/回车换行符/制表符/…)替换为指定字符/多个连续的空格转为一个空格
references
- linux - Can tr work with regex? - Unix & Linux Stack Exchange
- 简单替换可以用tr快速处理
-
tr is for transliteration. One popular use oftr is change the case of strings:
将文本转换为大写
$ echo 'this is a test' | tr a-z A-Z
THIS IS A TEST测试文本
- 将下面的文本写入到文件
file中
> file<<eof
getpid() returns the process ID (PID) of the calling process.
(This is often used by routines that generate unique temporary
filenames.)
getppid() returns the process ID of the parent of the calling
process. This will be either the ID of the process that created
this process using fork(), or, if that process has already
terminated, the ID of the process to which this process has been
reparented (either init(1) or a "subreaper" process defined via
the prctl(2) PR_SET_CHILD_SUBREAPER operation).
eof- 使用
cat -A检查空白字符的分布($,^)
└─[0] <> cat file -A
getpid() returns the process ID (PID) of the calling process.$
(This is often used by routines that generate unique temporary$
filenames.)$
$
getppid() returns the process ID of the parent of the calling$
process. This will be either the ID of the process that created$
this process using fork(), or, if that process has already$
terminated, the ID of the process to which this process has been$
reparented (either init(1) or a "subreaper" process defined via$
the prctl(2) PR_SET_CHILD_SUBREAPER operation).$- 文件2:写入到
ff中
> ff<<eof
line1 end
line2 end
123
456
eof- 空白符分部情况
┌─[cxxu@CxxuWin11] - [~] - [2022-04-24 02:17:01]
└─[0] <> cat ff -A
line1 end$
line2^Iend$
123$
456$将所有空白字符串(长度>0)的地方替换为一个空格
这种情况经常在复制pdf中的文本/man手册中的文本时需做的处理
sed&tr
本方案综合利用了sed按行处理的专业性(正则表达式的完整支持)和tr(对于多行文本间的字符操作的简单易行的优势)
-
sed -e 's/\s\+/ /g' file|tr "\n" ' '(此处没有使用扩展的正则-E选项,将+视为数量匹配符时需要\转义之) - 或者
cat file|sed -E 's/\s+/ /g'|tr '\n' ' '(使用扩展的正则表达式)
┌─[cxxu@CxxuWin11] - [~] - [2022-04-24 02:11:51]
└─[0] <> cat file|sed -E 's/\s+/ /g'|tr '\n' ' '
getpid() returns the process ID (PID) of the calling process. (This is often used by routines that generate unique temporary filenames.) getppid() returns the process ID of the parent of the calling process. This will be either the ID of the process that created this process using fork(), or, if that process has already terminated, the ID of the process to which this process has been reparented (either init(1) or a "subreaper" process defined via the prctl(2) PR_SET_CHILD_SUBREAPER operation).
