That's the biggest problem: some things are very simple, but other things fall off a cliff. For example, as a related task I ran into recently: how do you replace FOO with the contents of foo.txt? The natural way would be expanding it into a command line, but at least with sed that's no good even for nice short text files because / and \n are special. You can use a sed command to read a file which I didn't know existed until I looked it up, but it apparently has the delightful feature that "If file cannot be read for any reason, it is silently ignored and no error condition is set." You can use perl... you can use perl to easily do a lot of things that are really hard to do otherwise (including things as simple as matching a regex and printing capture groups), but at least to me it feels really awkward to wrong to mix two different full-fledged languages. Maybe I should just get over that, but I wish the whole thing were more coherent.
Interesting problem. Some quick head-scratching and googling didn't turn up anything useful on merging templates with awk and sed... then it hit me --- m4 is used for that:
Interesting solution; I should learn to use m4 for various tasks. Probably would have already if I didn't have such a negative visceral reaction to autotools :)
As for "capture groups", you can use lex. I wrote a "code generator" shell script to produce .l files and another script that compiles .l files to one-off utilities.
There is perhaps more coherence to the whole thing than you are aware of. Whether "Linux distros" or "OSX" have maintained that coherency I do not know.
Sounds useful, but it's not portable, and doesn't work on OS X. I suppose I could just switch to GNU sed, since I mostly care about interactive use, but thus far I haven't done so.
That's the biggest problem: some things are very simple, but other things fall off a cliff. For example, as a related task I ran into recently: how do you replace FOO with the contents of foo.txt? The natural way would be expanding it into a command line, but at least with sed that's no good even for nice short text files because / and \n are special. You can use a sed command to read a file which I didn't know existed until I looked it up, but it apparently has the delightful feature that "If file cannot be read for any reason, it is silently ignored and no error condition is set." You can use perl... you can use perl to easily do a lot of things that are really hard to do otherwise (including things as simple as matching a regex and printing capture groups), but at least to me it feels really awkward to wrong to mix two different full-fledged languages. Maybe I should just get over that, but I wish the whole thing were more coherent.