反斜线,反斜杆(escape [backslash])。 \1. 放在特殊符号之前,转义特殊符号的作用,仅表示特殊符号本身,这在字符串中常用; \2. 放在一行指令的最末端,表示紧接着的回车无效(其实也就是转义了Enter),后继新行的输入仍然作为当前指令的一部分。 10. ` 反引号/后引号-命令替换 反引号,后引号(Command substitution...
Let’s break down what’s going on in the Bash script you just created. Bash executes programs in order from the first line in your file to the last line. Theexprcommand can be used toevaluateBashexpressions. An expression is just a valid string of Bash code that, when run, produces a...
[[ n != 0 ]]# Constant test expressions[[ -e *.mpg ]]# Existence checks of globs[[$foo==0 ]]# Always true due to missing spaces[[ -n"$foo"]]# Always true due to literals[[$foo=~"fo+"]]# Quoted regex in =~[ foo =~ re ]# Unsupported [ ] operators[$1-eq"shellcheck"...
# PNG files in dir. for file in ~/Pictures/*.png; do printf '%s\n' "$file" done # Iterate over directories. for dir in ~/Downloads/*/; do printf '%s\n' "$dir" done # Brace Expansion. for file in /path/to/parentdir/{file1,file2,subdir/file3}; do printf '%s\n' "$fil...
In this example we declare simple bash variable and print it on the screen ( stdout ) with echo command. #!/bin/bash STRING="HELLO WORLD!!!" echo $STRING 1. 2. 3. Your backup script and variables: #!/bin/bash OF=myhome_directory_$(date +%Y%m%d).tar.gz ...
3.1.2.1 Escape Character A non-quoted backslash ‘\’ is the Bash escape character. It preserves the literal value of the next character that follows, with the exception ofnewline. If a\newlinepair appears, and the backslash itself is not quoted, the\newlineis treated as a line continuatio...
rsync,ssh: do not overescape spaces in remote filenames (#910) (e8dc253) source files using absolute paths for absolute BASH_SOURCE (e1a70c6) tar: Complete added files with long opts (c94bebb) update-alternatives: fix the "--help" parsing (07605cb)2.14...
The special parameters * and @ have special meaning when in double quotes (see PARAMETERS below). Words of the form $'string' are treated specially. The word expands to string, with backslash-escaped characters replaced as specified by the ANSI C standard. Backslash escape sequences, if ...
For instance, spaces normally indicate the boundary between strings in the array;例如,空格通常表示数组中字符串之间的边界。for that reason, the individual arguments are sometimes called "words".因此,有时将各个参数称为“单词”。But an argument may nonetheless have spaces in it;但是,论点中可能还有...
EN常用的内置命令忽略，来看看shell编程中其他一些重要的内置命令： 1、help：显示所有内置命令列表，或...