Bash Perl Tcl syntax diff

1. 进制数表示

Language	binary	octal	hexadecimal
bash	2#[0~1]	0[0~7]	0x[0~f] or 0X[0~f]
perl	0b[0~1]	0[0~7]	0x[0~f]
tcl	0b[0~1]	0o[0~7]	0x[0~f]

bash different base represntation reference

2. String length

Language	String length
bash	${#variable_store_string}
perl	length($variable_store_string)
tcl	string length variable_store_string

bash string length reference

perl string length reference

https://www.tutorialspoint.com/tcl-tk/tcl_strings.htm

3. String upper/lower

Language	String upper	String lower
bash	${variable_store_string^^}	${variable_store_string,,}
perl	uc($variable_store_string)	lc($variable_store_string)
tcl	string toupper variable_store_string	string tolower variable_store_string

# perl

\u 修改下一个字符为大写
\l 修改下一个字符小写 
\U 修改后面所有字符大写 
\L 修改后面所有字符小写 
\Q 使后面的所有字符都成为字面符号
\E 结束\U \L或\Q的效果

# =============================================================== #
 perl				 bash			       tcl

ucfirst				${var^}			string toupper 0/string totitle
lcfirst				${var,}			string tolower 0

# bash

declare -l var="strings"
declare -u var="strings"

bash upper/lower blog reference

declare command reference

tr command reference