expr can do this without a pipe: if expr november : nov then : do something fi the only catch is expr works with anchored strings, so if you want to match after the beginning you need to …

2012年8月8日 · expr is an external program used by Bourne shell(i.e. sh). Bourne shell didn't originally have any mechanism to perform simple arithmetic. It uses expr external program …

2022年4月11日 · What is expr doing in these two commands? For the first command, it seems expr found a match from the first character of abc and reports the matched length. But why …

2014年8月13日 · Furthermore, expr needs each number and operator to be passed as a separate parameter. Thus: expr 3 \* \( 2 + 1 \) Unless you're working on an antique unix system from the …

2020年10月18日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for …

2016年12月1日 · For one thing, bc supports big numbers while expr tops out at 2^63-1: $ expr 9223372036854775807 + 1 -9223372036854775807 $ echo "9223372036854775807 + 1" | bc …

2021年3月10日 · Do you recognize that using multiple values in expr at the same time would be a problem? What you have is something like expr 39806 45608 + 9. It would be better to tell us …

expr is a command that can also perform (basic integer) arithmetic, but then it's pointless to pipe its output to bc -l which also does mathematics. Choose one or the other, not both. Choose …

2019年9月2日 · expr: syntax error: unexpected argument ‘2’ expr: syntax error: unexpected argument ‘2’ I wanted to output a file called results_a_b where a and b are values defined in …

2013年6月14日 · Use the GNU Multiple Precision Arithmetic Library through the supplied run-expr program: Download and extract(you will need lzip): tar -xvf gmp-5.1.3.tar.lz; In the top …