好比 ./myProgram a b 和 ./myProgram a b 对于程序myProgram来说没有任何区别
贴上一段man bash供楼主参考
Word Splitting
The shell scans the results of parameter expansion, command substitution, and arithmetic expansion that did not occur within double quotes
for word splitting.
The shell treats each character of IFS as a delimiter, and splits the results of the other expansions into words on these characters. If
IFS is unset, or its value is exactly <space><tab><newline>, the default, then sequences of <space>, <tab>, and <newline> at the beginning
and end of the results of the previous expansions are ignored, and any sequence of IFS characters not at the beginning or end serves to
delimit words. If IFS has a value other than the default, then sequences of the whitespace characters space and tab are ignored at the
beginning and end of the word, as long as the whitespace character is in the value of IFS (an IFS whitespace character). Any character in
IFS that is not IFS whitespace, along with any adjacent IFS whitespace characters, delimits a field. A sequence of IFS whitespace charac‐
ters is also treated as a delimiter. If the value of IFS is null, no word splitting occurs.