commit 9005c2eaffbd3438cb94ccda7dbbd401a4beef7c
parent 152cfc65daccf3ed64097f30af1848abb86485fe
Author: Friedel Schön <[email protected]>
Date: Tue, 6 Aug 2024 14:45:55 +0200
xargs functionality
Diffstat:
| M | textselect.1 | | | 5 | ++++- |
| M | textselect.c | | | 410 | ++++++++++++++++++++++++++++++++++++++++++++----------------------------------- |
2 files changed, 231 insertions(+), 184 deletions(-)
diff --git a/textselect.1 b/textselect.1
@@ -16,7 +16,10 @@ is a utility that allows users to interactively select lines from a text file us
Display usage information and exit.
.TP
.B \-v
-Invert the selection of lines (selected lines become unselected and vice versa).
+Invert the selection of lines.
+.TP
+.B \-x
+Call command with lines as arguments.
.TP
.B \-o \fIoutput\fP
Specify an output file to save the selected lines. If not specified, the selected lines are printed to stdout.
diff --git a/textselect.c b/textselect.c
@@ -5,268 +5,312 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
-#include <unistd.h>
#include <sys/wait.h>
+#include <unistd.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;
+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);
+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;
+ 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");
+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;
+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);
+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]);
- }
- }
+ 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;
+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");
+ 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);
+ 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> [command ...]\n", argv0);
- exit(exitcode);
+ fprintf(stderr, "Usage: %s [-hvx] [-o output] <input> [command ...]\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();
+ 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:
+ case KEY_LEFT:
+ if (current_line > 0) {
+ (current_line)--;
+ if (current_line < start_line)
+ start_line--;
+ }
+ break;
+ case KEY_DOWN:
+ case KEY_RIGHT:
+ 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
- }
+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);
+void execute_command_xargs(int argc, char** argv) {
+ char** newargv;
+ int chosencount = argc + 1; // + NULL
+ for (int i = 0; i < line_count; i++)
+ if (chosen_lines[i] != invert_chosen)
+ chosencount++;
+
+ newargv = malloc(chosencount * sizeof(char*));
+ int newargc;
+ for (newargc = 0; newargc < argc; newargc++)
+ newargv[newargc] = argv[newargc];
+
+ size_t current = 0;
+ if (chosen_lines[0] != invert_chosen)
+ newargv[newargc++] = buffer;
+
+ for (size_t i = 0; i < buffer_ptr; i++) {
+ if (buffer[i] == '\0') {
+ current++;
+ if (chosen_lines[current] != invert_chosen)
+ newargv[newargc++] = &buffer[i + 1];
}
- ARGEND;
+ }
- if (argc == 0) {
- fprintf(stderr, "error: missing input\n");
- usage(1);
- }
+ newargv[newargc++] = NULL;
- load_file(argv[0]);
- SHIFT;
+ pid_t pid;
- display_window();
-
- if (argc == 0) {
- output_chosen_lines(output);
- } else {
- execute_command(argv);
- }
-
- free(buffer);
- free(chosen_lines);
+ if ((pid = fork()) == -1) die("fork");
+ if (pid == 0) {
+ execvp(newargv[0], newargv);
+ die("execvp");
+ }
+ wait(NULL);
+}
- return 0;
+int main(int argc, char* argv[]) {
+ char* output = NULL;
+ bool xargs = false;
+
+ argv0 = argv[0];
+ ARGBEGIN
+ switch (OPT) {
+ case 'h':
+ usage(0);
+ case 'v':
+ invert_chosen = true;
+ break;
+ case 'x':
+ xargs = 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 if (!xargs) {
+ execute_command(argv);
+ } else {
+ execute_command_xargs(argc, argv);
+ }
+
+ free(buffer);
+ free(chosen_lines);
+
+ return 0;
}
