How to create any customized Unix command? - c++

I want to create one unix command, which will unzip the folder.
so, I am searching for the code, but I am not aware that how should I use such code to make Unix command?
I have gone through various questions & answers but I don't get any perfect information.
So, can any one please suggest me any code (in C++ or C or any language to make exe) and to use it as a Unix command.
NOTE: I know command like 'unzip' is available in 'Mks toolkit' type of software but we can not use it, so I want to make command which can run through 'command prompt'

If you want to add a command, you only need to create your executable and put its link in the /usr/bin folder.
Just compile your code and set a link to it's executable like this:
ln -s /path/to/your_executable /usr/bin/command_name
If there exists a command that you need to modify, you should set an alias to it. For example, you want ls -1 to run whenever ls is used, then you only need to use the command:
alias ls=ls -1
or put the same command in the .bashrc file in your home directory.

Related

Github Actions path does not update

Right now, I'm trying to build a tool from source and use it to build a C++ project. I'm able to extract the tar file (gcc-arm-none-eabi). But, when I try to add it to path (using $GITHUB_PATH, not add-path), the path doesn't apply on my next action and I can't build the file. The error states that it can't find the gcc-arm-none-eabi toolset, which means that it didn't go to path.
Here's the script for the entrypoint of the first function (make is ran in the next action to allow for path to apply)
echo "Downloading ARM Toolchain"
# The one from apt isn't updated so I have to build from source
curl -L https://developer.arm.com/-/media/Files/downloads/gnu-rm/10-2020q4/gcc-arm-none-eabi-10-2020-q4-major-x86_64-linux.tar.bz2 -o gcc-arm-none-eabi.tar.bz2
tar -xjf gcc-arm-none-eabi.tar.bz2
echo "/github/workspace/gcc-arm-none-eabi-10-2020-q4-major/bin" >> $GITHUB_PATH
I can't even debug by seeing what's in the path because running echo $(PATH) just says that PATH cannot be found. What should I do?
I can't even debug by seeing what's in the path because running echo $(PATH) just says that PATH cannot be found. What should I do?
First, PATH is not a command so if you want to print its value, it would be something like echo "${PATH}" or echo "$PATH"
Then, if you want to add a value to an existing environment variable, it would be something like
export PATH="${PATH}:/github/workspace/gcc-arm-none-eabi-10-2020-q4-major/bin"
EDIT: seems not a valid way to add something to the path using Github Actions, meanwhile it seems correct in the question. To get more details: https://docs.github.com/en/free-pro-team#latest/actions/reference/workflow-commands-for-github-actions#adding-a-system-path . Thanks to Benjamin W. for pointing this out in the comments.
Finally I think it would be a better fit if you use a docker image that already contains that kind of dependancies (you could easily write your own Dockerfile if this image doesn't already exists). Github action is designed to use docker (or OCI containers) image that contains the dependancies you need to perform your build actions. You should take a look here: https://docs.github.com/en/free-pro-team#latest/actions/creating-actions/dockerfile-support-for-github-actions

How to rename bazelisk to bazel

I am currently trying, without great success, to build tensorflow from source.
As suggested here: https://www.tensorflow.org/install/source, I tried to do so by installing bazelisk. Unfortunately, I wasn't able to do so as the ./compile cannot find bazel as bazelisk replaces it.
This link: https://github.com/bazelbuild/bazelisk/issues/122 suggested to alias or rename the environment variable to "bazel" in the PATH.
As described in the issue above, aliasing did not work out for the configure.py.
My next step would be to rename it but I, unfortunately, was not able to figure out how the renaming of environment works under Linux.
I did add the following:export PATH=$PATH:$(go env GOPATH)/bin
to my .profile under my /home folder, which, the way I understand it, adds the path to Bazelisk binaries to my environment path but I am not sure how the renaming would work in this situation.
Would it be possible to explain how I could proceed?
Download the bazelisk binary from the releases page and save the file as bazel in a directory somewhere in your $PATH.
For example, if you have export PATH=$PATH:$HOME/bin in your .profile/.bashrc/.bash_profile, and in $HOME/bin, store the bazelisk binary as $HOME/bin/bazel.
You can have 2 more options:
sudo ln -s /usr/local/bin/bazelisk /usr/local/bin/bazel which makes a symlink to bazelisk (personally i prefer it, because its more explicit)
alias bazel='bazelisk' in your ~/.zshrc, ~/.bashrc or ~/.profile. This also works well, but there could be some issues if you want to run vim-bazel and such.

How to install ninja-build for C++

https://github.com/ninja-build/ninja/releases
I have downloaded the ninja-win.zip folder and extracted it. When I open it, there is a single .exe file in the entire folder. When I double click it a cmd window flashes for a split second. I have also tried running it as administrator, but the same thing happens. What I don't understand is, what am I expected to do with this .exe file?
You must open a terminal (cmd.exe on Windows) and type something like ninja -f /path/to/buld/file. You may also wish to modify the PATH environment variable so that Windows knows where to find the Ninja executable, depending on your setup.
You can simple download ninja.exe file from this Link
https://github.com/ninja-build/ninja/releases
After that you just have to add the path to your ninja.exe file to your windows environment variables and then you can use ninja commands from anywhere in windows.
1. Open cmd in your Project Directory
2. There are guides on the internet on where to save the Ninja.exe so that it'll be callable in Cmd without specifying directory. Either follow them or:
i, Specify Directory when Calling Ninja. Putting "ninja" in Cmd actually calls Ninja.exe and is the same as something like "C:\users\user1\downloads\Ninja". or:
ii, Save Ninja.exe in the same directory as Project.
3. proceed with rest of the command.
Therefore the Final Command would be:
"C:\users\user\downloads\Ninja.exe" -f "D:\Projects\Project1"

Dynamically-created 'zip' command not excluding directories properly

I'm the author of a utilty that makes compressing projects using zip a bit easier, especially when you have to compress regularly, such as for updating projects submitted to an application store (like Chrome's Web Store).
I'm attempting to make quite a few improvements, but have run into an issue, described below.
A Quick Overview
My utility's command format is similar to command OPTIONS DEST DIR1 {DIR2 DIR3 DIR4...}. It works by running zip -r DEST.zip DIR1; a fairly simple process. The benefit to my utility, however, is the ability to use a predetermined file (think .gitignore) to ignore specific files/directories, or files/directories which match a pattern.
It's pretty simple -- if the "ignorefile" exists in a target directory (DIR1, DIR2, DIR3, etc), my utility will add exclusions to the zip -r DEST.zip DIR1 command using the pattern -x some_file or -x some_dir/*.
The Issue
I am running into an issue with directory exclusion, however, and I can't quite figure out why (this is probably be because I am still quite the sh novice). I'll run through some examples:
Let's say that I want to ignore two things in my project directory: .git/* and .gitignore. Running command foo.zip project_dir builds the following command:
zip -r foo.zip project -x project/.git/\* -x project/.gitignore
Woohoo! Success! Well... not quite.
In this example, .gitignore is not added to the compressed output file, foo.zip. The directory, .git/*, and all of it's subdirectories (and files) are added to the compressed output file.
Manually running the command:
zip -r foo.zip project_dir -x project/.git/\* -x project/.gitignore
Works as expected, of course, so naturally I am pretty puzzled as to why my identical, but dynamically-built command, does not work.
Attempted Resolutions
I have attempted a few different methods of resolving this to no avail:
Removing -x project/.git/\* from the command, and instead adding each subdirectory and file within that directory, such as -x project/.git/config -x project/.git/HEAD, etc (including children of subdirectories)
Removing the backslash before the asterisk, so that the resulting exclusion option within the command is -x project/.git/*
Bashing my head on the keyboard in angst (I'm really surprised this didn't work, it usually does)
Some notes
My utility uses /bin/sh; I would prefer to keep it that way for maximum compatibility.
I am aware of the git archive feature -- my use of .git/* and .gitignore in the above example is simply as an example; my utility is not dependent on git nor is used exclusively for projects which are git repositories.
I suspected the problem would be in the evaluation of the generated command, since you said the same command when executed directly did right.
So as the comment section says, I think you already found the correct solution. This happens because if you run that variable directly, some things like globs can be expanded directly, instead of passed to the command. And arguments may be messed up, depending on the situation.
Yes, in that case:
eval $COMMAND
is the way to go.

How to bundle C/C++ code with C-shell-script?

I have a C shell script that calls two
C programs - one after the another
with some file handling before,
in-between and afterwards.
Now, as such I have three different files - one C shell script and 2 .c files.
I need to give this script to other users. The problem is that I have to distribute three files - which the users must keep in the same folder and then execute the script.
Is there some better way to do this?
[I know I can make one C code file out of those two... but I will still be left with a shell script and a C code. Actually, the two C codes do entirely different things... so I want them to be separate]
Sounds like you're worried that your users aren't savy enough to figure out how to resolve issues like command not found errors and the like. If absolutely MUST hide "complexity" of a collection of files you could have your script create the other files. In most other circumstances I would suggest that this approach is only going to increase your support workload since semi-experienced users are less likely to know how to troubleshoot the process.
If you choose to rely on the presence of a compiler on the system that you are running on you can store the C code as a collection of cat $STRING >> file.c commands to to create your two C files, which you then compile and use.
If you would want to use pre-compiled programsn instead then the same basic process can be used except instead use xxd to both generate the strings in your script and reverse the conversion process to give you working binaries. Note: Remember to chmod the binary so that it is executable.
use shar command to create self-extracting archive.
or better yet use unzipsfx with AUTORUN option.
This provides users with ONE file, and only ONE command to execute (as opposed to one for untarring and one for execution).
NOTE: The unzip command to run should use "-n" option, that way only the first run would extract the files and the subsequent would skip the extraction.
Use a zip or tar file? And you do realize that .c files aren't executable, you need to compile & link them first?
You can include the c code inside the shell script as a here document:
#!/bin/bash
cat > code.c << EOF
line #1
line #2
...
EOF
# compile
# execute
If you want to get fancy, you can test for the existence of the executable and skip compiling them if they exists.
If you are doing much shell programming, the rest of the Advanced Bash-Scripting Guide is worth looking at as well.