66 lines
1.7 KiB
Markdown
66 lines
1.7 KiB
Markdown
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# The `tr` command
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The tr command in UNIX is a command line utility for translating or deleting characters.
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It supports a range of transformations including uppercase to lowercase, squeezing repeating characters, deleting specific characters and basic find and replace.
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It can be used with UNIX pipes to support more complex translation. tr stands for translate.
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### Examples:
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1. Convert all lowercase letters in file1 to uppercase.
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```
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$ cat file1
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foo
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bar
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baz
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tr a-z A-Z < file1
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FOO
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BAR
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BAZ
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```
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2. Make consecutive line breaks into one.
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```
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$ cat file1
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foo
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bar
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baz
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$ tr -s "\n" < file1
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foo
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bar
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baz
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```
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3. Remove the newline code.
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```
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$ cat file1
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foo
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bar
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baz
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$ tr -d "\n" < file1
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foobarbaz%
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```
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### Syntax:
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The general syntax for the tr command is as follows:
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```
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tr [options] string1 [string2]
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```
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### Additional Flags and their Functionalities:
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| **Short Flag** | **Long Flag** | **Description** |
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| :------------- | :------------ | :------------------------------------------------------------------------------------------------------------ |
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| `-C` | | Complement the set of characters in string1, that is `-C ab` includes every character except for `a` and `b`. |
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| `-c` | | Same as -C. |
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| `-d` | | Delete characters in string1 from the input. |
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| `-s` | | If there is a sequence of characters in string1, combine them into one. |
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