commit 2ce1130421b517eac05514a7834c842b8d5f9182
Author: Friedel Schön <[email protected]>
Date: Tue, 6 Aug 2024 13:46:00 +0200
first commit
Diffstat:
| A | .clang-format | | | 46 | ++++++++++++++++++++++++++++++++++++++++++++++ |
| A | LICENSE | | | 18 | ++++++++++++++++++ |
| A | Makefile | | | 20 | ++++++++++++++++++++ |
| A | arg.h | | | 19 | +++++++++++++++++++ |
| A | readme.md | | | 83 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | textselect.1 | | | 58 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | textselect.c | | | 272 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
7 files changed, 516 insertions(+), 0 deletions(-)
diff --git a/.clang-format b/.clang-format
@@ -0,0 +1,46 @@
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+BreakInheritanceList: BeforeComma
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+IncludeBlocks: Regroup
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+IndentPPDirectives: AfterHash
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+TabWidth: 4
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diff --git a/LICENSE b/LICENSE
@@ -0,0 +1,17 @@
+Copyright (c) 2023 Friedel Schön <[email protected]>
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+\ No newline at end of file
diff --git a/Makefile b/Makefile
@@ -0,0 +1,20 @@
+CFLAGS += -O2 -Wall -Wextra -Wpedantic
+LDFLAGS += -lncurses
+PREFIX = /usr
+
+.PHONY: all install clean
+
+all: textselect
+
+textselect.o: textselect.c arg.h
+ $(CC) -c $< -o $@ $(CFLAGS) $(CPPFLAGS)
+
+textselect: textselect.o
+ $(CC) $< -o $@ $(LDFLAGS)
+
+install: textselect textselect.1
+ cp textselect $(PREFIX)/bin/
+ cp textselect.1 $(PREFIX)/share/man/man1/
+
+clean:
+ rm -f textselect textselect.o
diff --git a/arg.h b/arg.h
@@ -0,0 +1,19 @@
+#pragma once
+
+#define SHIFT (argc--, argv++)
+
+#define ARGBEGIN \
+ for (SHIFT; *argv && *argv[0] == '-'; SHIFT) { \
+ if ((*argv)[1] == '-' && (*argv)[2] == '\0') { \
+ SHIFT; \
+ break; \
+ } \
+ for (char* opt = *argv + 1; *opt; opt++) {
+
+#define ARGEND \
+ } \
+ }
+
+#define OPT (*opt)
+#define ARGF (argv[1] ? (SHIFT, *argv) : NULL)
+#define EARGF(usage) (argv[1] ? ARGF : (printf("'-%c' requires an argument\n", *opt), usage, NULL))
diff --git a/readme.md b/readme.md
@@ -0,0 +1,83 @@
+# weakbox
+
+**weakbox** is a tool for Linux designed to create a weak (not secured) container for running programs from another Linux distribution. It is particularly useful for executing glibc-based programs (mostly closed-source software) under systems that are musl-based.
+
+## Features
+
+- Create a container environment for running programs from different Linux distributions.
+- Bind mount directories from the host system into the container.
+- Map user and group IDs inside the container.
+- Customizable root path for the container.
+- Option to run commands within the container as `root`.
+
+## Installation
+
+To install **weakbox**, simply clone the repository and compile the source code:
+
+```bash
+git clone https://github.com/friedelschoen/weakbox.git
+cd weakbox
+make
+sudo make install # which installs /usr/bin/weakbox and /usr/share/man/man1/weakbox.1
+sudo make PREFIX=... install # which installs $PREFIX/bin/weakbox and $PREFIX/share/man/man1/weakbox.1
+```
+
+## Usage
+
+Run **weakbox** with the desired options and command to execute within the container:
+
+```bash
+weakbox [options] command ...
+```
+
+By default `command` is executed, if command is omitted current shell or `/bin/bash` is executed.
+
+### Options
+
+- `-h`: Display usage information.
+- `-s`: Run the specified command within the container as root.
+- `-v`: Enable verbose mode for debugging purposes.
+- `-r path`: Set the root path of the container to `path`. By default the container lays at `$WEAKBOX`.
+- `-b source[:target]`: Bind mount the specified source directory to the target directory within the container. Target is relative to `root`.
+- `-B source`: Remove a default bind mount from the container.
+- `-u uid[:uid]`: Map user IDs inside the container.
+- `-g gid[:gid]`: Map group IDs inside the container.
+
+### Default Mounts
+- `/dev`: directory containing all devices
+- `/home`: home directories of users
+- `/proc`: directories containing information about processes
+- `/sys`: system directories for various devices
+- `/tmp`: temporary directory
+- `/run`: temporary directory for daemons and long-running programs
+- `/etc/resolv.conf`: nameserver-resolution configuration
+- `/etc/passwd`: file containing information about users
+- `/etc/group`: file containing information about groups
+
+### Examples
+
+1. Run a program within the container:
+
+```bash
+weakbox -s /path/to/program
+```
+
+2. Create a container with custom root path and bind mount directories:
+
+```bash
+weakbox -r /custom/root -b /host/dir:/dir /path/to/program
+```
+
+3. Map user and group IDs inside the container:
+
+```bash
+weakbox -u 1000:1000 -g 1000:1000 /path/to/program
+```
+
+## Contributing
+
+Contributions are welcome! Feel free to submit bug reports, feature requests, or pull requests through GitHub issues and pull requests.
+
+## License
+
+This project is licensed under the zlib-license. See the [LICENSE](LICENSE) file for details.
diff --git a/textselect.1 b/textselect.1
@@ -0,0 +1,58 @@
+.TH TEXTSELECT 1 "August 2024" "1.0" "Text Selection Tool"
+.SH NAME
+textselect \- A command-line tool to mark and select lines from a text file using ncurses.
+
+.SH SYNOPSIS
+.B textselect
+[\-v]
+.IR file
+
+.SH DESCRIPTION
+.B textselect
+is a command-line tool that allows users to interactively mark and select lines from a text file using ncurses. It displays the contents of a file, enables navigation through the lines, and allows lines to be marked. On exit, it prints the selected lines to the standard output.
+
+.SH OPTIONS
+.TP
+.B \-v
+Invert the selection mode. When this option is used, lines that are not marked will be printed upon exit.
+
+.SH USAGE
+Navigate through the file using the arrow keys. Mark or unmark a line by pressing the spacebar. Exit the program by pressing 'q'.
+
+The program reads the specified file and displays its contents in an ncurses window. The following keys are used for navigation and selection:
+.TP
+.UP
+Move the cursor up by one line.
+.TP
+.DOWN
+Move the cursor down by one line.
+.TP
+.SPACE
+Toggle the mark on the current line.
+.TP
+.q
+Exit the program and print the marked lines.
+
+.SH EXAMPLES
+.TP
+Select lines from a file:
+.B
+textselect myfile.txt
+.TP
+Invert the selection:
+.B
+textselect \-v myfile.txt
+
+.SH AUTHOR
+Written by [Your Name].
+
+.SH REPORTING BUGS
+Report bugs to <[email protected]>.
+
+.SH COPYRIGHT
+This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
+
+.SH SEE ALSO
+.BR ncurses (3X),
+.BR vi (1),
+.BR less (1)
diff --git a/textselect.c b/textselect.c
@@ -0,0 +1,272 @@
+#include "arg.h"
+
+#include <fcntl.h>
+#include <ncurses.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+#define READBUFFER 512
+#define BUFFERGROW 512
+
+#define NORETURN __attribute__((noreturn))
+
+char *buffer = NULL;
+size_t buffer_ptr = 0;
+size_t buffer_alloc = 0;
+int line_count = 0;
+bool *chosen_lines = NULL;
+bool invert_chosen = false;
+char *argv0;
+
+/**
+ * @brief Handles error messages and exits the program.
+ *
+ * @param message Error message to print.
+ */
+void die(const char *message) {
+ perror(message);
+ exit(EXIT_FAILURE);
+}
+
+/**
+ * @brief Allocates memory for the buffer, growing it by BUFFERGROW bytes.
+ */
+void grow_buffer(void) {
+ char *new_buf;
+ if ((new_buf = realloc(buffer, buffer_alloc += BUFFERGROW)) == NULL) {
+ die("allocating buffer");
+ }
+ buffer = new_buf;
+}
+
+/**
+ * @brief Loads a file into memory, storing its lines in the buffer.
+ *
+ * @param filename Name of the file to load, or NULL to read from stdin.
+ */
+void load_file(const char *filename) {
+ static char readbuf[READBUFFER];
+ ssize_t nread;
+ int fd;
+
+ fd = (filename == NULL) ? STDIN_FILENO : open(filename, O_RDONLY);
+ if (fd == -1) die("Failed to open file");
+
+ while ((nread = read(fd, readbuf, sizeof(readbuf))) > 0) {
+ for (ssize_t i = 0; i < nread; i++) {
+ if (buffer_ptr == buffer_alloc) grow_buffer();
+
+ if (readbuf[i] == '\n') {
+ if (buffer[buffer_ptr - 1] != '\0') {
+ buffer[buffer_ptr++] = '\0';
+ line_count++;
+ }
+ } else {
+ buffer[buffer_ptr++] = readbuf[i];
+ }
+ }
+ }
+
+ buffer[buffer_ptr++] = '\0';
+ if (fd > 2) close(fd);
+
+ chosen_lines = calloc(line_count, sizeof(bool));
+ if (chosen_lines == NULL) die("allocating chosen_lines");
+}
+
+/**
+ * @brief Retrieves a line from the buffer.
+ *
+ * @param line Line number to retrieve.
+ * @return Pointer to the start of the line.
+ */
+char *get_line(size_t line) {
+ size_t current = 0;
+ if (line == 0) return buffer;
+ for (size_t i = 0; i < buffer_ptr; i++) {
+ if (buffer[i] == '\0') {
+ current++;
+ if (current == line) return &buffer[i + 1];
+ }
+ }
+ return NULL;
+}
+
+/**
+ * @brief Prints lines to the ncurses window.
+ *
+ * @param win ncurses window to print to.
+ * @param current_line Line currently selected.
+ * @param start_line Line to start printing from.
+ * @param max_y Maximum number of lines to print.
+ */
+void draw_lines(WINDOW *win, int current_line, int start_line, int max_y) {
+ werase(win);
+ for (int i = 0; i < max_y && (start_line + i) < line_count; i++) {
+ if ((start_line + i) == current_line) wattron(win, A_REVERSE);
+ if (chosen_lines[start_line + i] != invert_chosen) wattron(win, A_BOLD);
+ mvwprintw(win, i, 0, "%s", get_line(start_line + i));
+ wattroff(win, A_REVERSE | A_BOLD);
+ }
+ wrefresh(win);
+}
+
+/**
+ * @brief Prints the chosen lines to the specified file descriptor.
+ *
+ * @param fd File descriptor to print to.
+ */
+void output_chosen_lines_fd(int fd) {
+ size_t current = 0;
+ if (chosen_lines[0] != invert_chosen)
+ dprintf(fd, "%s\n", buffer);
+
+ for (size_t i = 0; i < buffer_ptr; i++) {
+ if (buffer[i] == '\0') {
+ current++;
+ if (chosen_lines[current] != invert_chosen)
+ dprintf(fd, "%s\n", &buffer[i + 1]);
+ }
+ }
+}
+
+/**
+ * @brief Prints the chosen lines to the specified output file.
+ *
+ * @param filename Name of the output file.
+ */
+void output_chosen_lines(char *filename) {
+ int fd;
+
+ fd = (filename == NULL) ? STDOUT_FILENO : open(filename, O_WRONLY | O_TRUNC | O_CREAT, 0664);
+ if (fd == -1) die("Failed to open file");
+
+ output_chosen_lines_fd(fd);
+}
+
+/**
+ * @brief Displays usage information and exits the program.
+ *
+ * @param exitcode Exit code.
+ */
+NORETURN void usage(int exitcode) {
+ fprintf(stderr, "Usage: %s [-hv] [-o output] <input>\n", argv0);
+ exit(exitcode);
+}
+
+/**
+ * @brief Initializes and handles the ncurses window for line selection.
+ */
+void display_window(void) {
+ initscr();
+ cbreak();
+ noecho();
+ keypad(stdscr, TRUE);
+
+ int current_line = 0;
+ int start_line = 0;
+ int ch;
+ int max_y = getmaxy(stdscr);
+
+ draw_lines(stdscr, current_line, start_line, max_y);
+
+ while ((ch = getch()) != 'q') {
+ switch (ch) {
+ case KEY_UP:
+ if (current_line > 0) {
+ (current_line)--;
+ if (current_line < start_line)
+ start_line--;
+ }
+ break;
+ case KEY_DOWN:
+ if (current_line < line_count - 1) {
+ (current_line)++;
+ if (current_line >= start_line + max_y)
+ start_line++;
+ }
+ break;
+ case 'v':
+ invert_chosen = !invert_chosen;
+ break;
+ case KEY_ENTER:
+ case ' ':
+ chosen_lines[current_line] = !chosen_lines[current_line];
+ break;
+ }
+ draw_lines(stdscr, current_line, start_line, max_y);
+ }
+
+ endwin();
+}
+
+/**
+ * @brief Executes a command and passes the chosen lines as stdin.
+ *
+ * @param argv Command and its arguments.
+ */
+void execute_command(char **argv) {
+ int pipefd[2];
+ pid_t pid;
+
+ if (pipe(pipefd) == -1) die("pipe");
+
+ if ((pid = fork()) == -1) die("fork");
+
+ if (pid == 0) { // Child process
+ close(pipefd[1]); // Close write end of the pipe
+ dup2(pipefd[0], STDIN_FILENO); // Redirect stdin to read end of the pipe
+ execvp(argv[0], argv);
+ die("execvp"); // If execvp fails
+ } else { // Parent process
+ close(pipefd[0]); // Close read end of the pipe
+ output_chosen_lines_fd(pipefd[1]);
+ close(pipefd[1]); // Close write end after writing
+ wait(NULL); // Wait for the child process to finish
+ }
+}
+
+int main(int argc, char *argv[]) {
+ char *output = NULL;
+
+ argv0 = argv[0];
+ ARGBEGIN
+ switch (OPT) {
+ case 'h':
+ usage(0);
+ case 'v':
+ invert_chosen = true;
+ break;
+ case 'o':
+ output = EARGF(usage(1));
+ break;
+ default:
+ fprintf(stderr, "error: unknown option '-%c'\n", OPT);
+ usage(1);
+ }
+ ARGEND;
+
+ if (argc == 0) {
+ fprintf(stderr, "error: missing input\n");
+ usage(1);
+ }
+
+ load_file(argv[0]);
+ SHIFT;
+
+ display_window();
+
+ if (argc == 0) {
+ output_chosen_lines(output);
+ } else {
+ execute_command(argv);
+ }
+
+ free(buffer);
+ free(chosen_lines);
+
+ return 0;
+}
