Assignment in subshells echo foo|read bar echo $bar Confusing time(1) for builtin time--format=%s sleep10 ~ in quotes rm"~/my file.txt" Single, quoted 'for' argument forfin"*.ogg"dorm $f;done Arithmetic truncation echo $((n/180*100)) Functions used externally f(){rm file...
Single quotes in bash will suppress special meaning of every meta characters. Therefore meta characters will be read literally. It is not possible to use another single quote within two single quotes not even if the single quote is escaped by backslash. #!/bin/bash #Declare bash string variab...
3.1.2.2 Single Quotes Enclosing characters in single quotes (‘'’) preserves the literal value of each character within the quotes. A single quote may not occur between single quotes, even when preceded by a backslash. 单引号包围的字符保留了在引号里面每个字符的字面意义。在单引号之间不允许出现...
Double quotes (”“) enable variable expansion and the interpretation of certain special characters, while single quotes (‘‘) maintain the literal value of each character. Q: What can you do with the tab space in printf? The tab space inprintf(\t) can be used to create horizontal spacing...
When the “echo” command is used with the single quotes, each character of the string is parsed without any expansion. That means if any Bash variable is enclosed with the single quotes (”), the variable name is printed in place of the value of the variable. The uses of single quotes...
*These subscripts differonly when the word appears within double quotes. If the word is double-quoted, ${name[*]} expands toa single wordwith the value of each array memberseparatedby the first character of the IFS variable, ...
The single quotes tell bash to print the characters specified within the quotes, i.e., the variable name. On the other hand, double quotes interpolate the input and display the variable's value. Note:The$character causes shell expansion and instructs bash to replace all the characters after ...
${!name[@]}and${!name[*]}expand to the indices assigned in array variable name. The treatment when in double quotes is similar to the expansion of the special parameters @ and * within double quotes. 即,使用*时,如果用双引号把整个表达式括起来,例如写为"${!name[*]}"、或者"${name[*...
prompt string special char translation and variable expansion auto-export of variables in initial environment command search finds functions before builtins bash return builtin will exit a file sourced with `.' builtins: cd -/-L/-P, exec -l/-c/-a, echo -e/-E, hash -d/-l/-p/-t. ...
Concatenate Strings in Bash String Comparison in Bash Scripts Bash Associative Arrays Incrementing and Decrementing Variables in Bash Using Single and Double Quotes in Bash Scripts The Bash for Loop 25 Common Bash Commands Knowledge of Bash commands and concepts is fundamental to writing effective scrip...