{"id":3997,"date":"2011-11-16T15:36:38","date_gmt":"2011-11-16T20:36:38","guid":{"rendered":"http:\/\/mjtsai.com\/blog\/?p=3997"},"modified":"2011-11-16T15:36:40","modified_gmt":"2011-11-16T20:36:40","slug":"arithmetic-expressions-in-shell-scripts","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2011\/11\/16\/arithmetic-expressions-in-shell-scripts\/","title":{"rendered":"Arithmetic Expressions in Shell Scripts"},"content":{"rendered":"<p><a href=\"http:\/\/blog.plover.com\/prog\/bash-expr.html\">Mark Dominus<\/a>:<\/p>\n<blockquote cite=\"http:\/\/blog.plover.com\/prog\/bash-expr.html\"><p>I had assumed that bc was a later development than expr, but it appeared in Unix version 6, while expr did not appear until version 7. So then I thought perhaps expr had been thrown in as a demonstration of yacc, but no, yacc was already present in version 5, and anyway, bc was written with yacc. So I no longer have any workable theory about who perpetrated expr, or why.<\/p><\/blockquote>","protected":false},"excerpt":{"rendered":"<p>Mark Dominus: I had assumed that bc was a later development than expr, but it appeared in Unix version 6, while expr did not appear until version 7. So then I thought perhaps expr had been thrown in as a demonstration of yacc, but no, yacc was already present in version 5, and anyway, bc [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"apple_news_api_created_at":"","apple_news_api_id":"","apple_news_api_modified_at":"","apple_news_api_revision":"","apple_news_api_share_url":"","apple_news_coverimage":0,"apple_news_coverimage_caption":"","apple_news_is_hidden":false,"apple_news_is_paid":false,"apple_news_is_preview":false,"apple_news_is_sponsored":false,"apple_news_maturity_rating":"","apple_news_metadata":"\"\"","apple_news_pullquote":"","apple_news_pullquote_position":"","apple_news_slug":"","apple_news_sections":"\"\"","apple_news_suppress_video_url":false,"apple_news_use_image_component":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-3997","post","type-post","status-publish","format-standard","hentry","category-programming-category"],"apple_news_notices":[],"_links":{"self":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/3997","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/comments?post=3997"}],"version-history":[{"count":1,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/3997\/revisions"}],"predecessor-version":[{"id":3998,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/3997\/revisions\/3998"}],"wp:attachment":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/media?parent=3997"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/categories?post=3997"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/tags?post=3997"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}