41–50 of 115 posts
The simplest thing I know that is able to do that is coccinelle, but even coccinelle is not handy enough.
We need a simpler regex format. One that allows easy searching and replacing in source code. Of course, some IDE's already to that pretty well, but I'd like to be able to do it from the command line with a stand alone tool I can easily use in scripts. The simplest thing I know that is able to do that is coccinelle, but even coccinelle is not handy enough.
I've always had trouble getting `for` loops to work predictably, so my common loop pattern is this: grep -l -r pattern /path/to/files | while read x; do echo $x; done or the like. This uses bash read to split the input line into words, then each word can be accessed in the loop with variable `$x`. Pipe friendly and doesn't use a subshell so no unexpected scoping issues. It also doesn't require futzing around with arr…
For me I always used for loops and only recently (after a decade of using Linux daily) have learned about the power of piped-loops. It’s strange to me you are more comfortable with those than for loops, but I think it does make sense as you’re letting a program generate the list to iterate over. A pain point in for loops is getting that right, e.g. there isn’t a good way to iterate over files with spaces in them usin…
If those files came as arguments, you can use a for-loop as long as they're kept in an array:
for f in "${files[@]}";
for-loops seem preferable for working with filenames. If a command is generating the list, then something like `xargs -0` is preferable.
> 1. Find and replace a pattern in a codebase with capture groups > git grep -l pattern | xargs gsed -ri 's|pat(tern)|\1s are birds|g' Or, in IDEA, Ctrl-Shift-r, put "pat(tern)" in the first box and "$1s are birds" in the second box, Alt-a, boom. Infinitely easier to remember, and no chance of having to deal with any double escaping.
We need a simpler regex format. One that allows easy searching and replacing in source code. Of course, some IDE's already to that pretty well, but I'd like to be able to do it from the command line with a stand alone tool I can easily use in scripts. The simplest thing I know that is able to do that is coccinelle, but even coccinelle is not handy enough.
I want to like this, but the for loop is unnecessarily messy, and not correct. for route in foo bar baz do curl localhost:8080/$route done That's just begging go wonky. Should be stuff="foo bar baz" for route in $stuff; do echo curl localhost:8080/$route done Some might say that it's not absolutely necessary to abstract the array into a variable and that's true, but it sure does make edits a lot easier. And, the orig…
Here's a few examples from my command history:
for ((i=0;i> 1. Find and replace a pattern in a codebase with capture groups > git grep -l pattern | xargs gsed -ri 's|pat(tern)|\1s are birds|g' Or, in IDEA, Ctrl-Shift-r, put "pat(tern)" in the first box and "$1s are birds" in the second box, Alt-a, boom. Infinitely easier to remember, and no chance of having to deal with any double escaping.
Using an IDE kind of handicaps you to only working with your IDE though. The shell works everywhere for every use case.
> git bisect is the "real" way to do this, but it's not something I've ever needed uh, yeah, you did need it, that's why you came up with "2. Track down a commit when a command started failing". Seriously though, git bisect is really useful to track down that bug in O(log n) rather than O(n).
I wish my usage of bisect were that trivial, though. Usually I need to find a bug in a giant web app. Which means finding a good commit, doing the npm install/start dance, etc. for each round.
I've always had trouble getting `for` loops to work predictably, so my common loop pattern is this: grep -l -r pattern /path/to/files | while read x; do echo $x; done or the like. This uses bash read to split the input line into words, then each word can be accessed in the loop with variable `$x`. Pipe friendly and doesn't use a subshell so no unexpected scoping issues. It also doesn't require futzing around with arr…
For me I always used for loops and only recently (after a decade of using Linux daily) have learned about the power of piped-loops. It’s strange to me you are more comfortable with those than for loops, but I think it does make sense as you’re letting a program generate the list to iterate over. A pain point in for loops is getting that right, e.g. there isn’t a good way to iterate over files with spaces in them usin…
https://bash.cyberciti.biz/guide/$IFS
Something I wish I'd learned 23 years ago instead of 3 years ago :(
I've always had trouble getting `for` loops to work predictably, so my common loop pattern is this: grep -l -r pattern /path/to/files | while read x; do echo $x; done or the like. This uses bash read to split the input line into words, then each word can be accessed in the loop with variable `$x`. Pipe friendly and doesn't use a subshell so no unexpected scoping issues. It also doesn't require futzing around with arr…
> I've always had trouble getting `for` loops to work predictably, so my common loop pattern is this: The problem with the pipe-while-read pattern is that you can't modify variables in the loop, since it runs in a subshell.
Both OSH and zsh behave that way by default, which was tangential to a point in the latest release notes https://news.ycombinator.com/item?id=29292187
Another trick I've seen in POSIX shell is to add a subshell after the pipeline until the last time you want to read the variable. Like
cat foo.txt | ( while read line; do
f=$line
done
echo "we're still in the subshell f=$f"
)