Simple embedded shell with runtime pluggable commands.
Implements a simple unix-like shell for embedded systems with a pluggable command architecture.
SimpleShell.cpp
- Committer:
- shimniok
- Date:
- 2018-12-21
- Revision:
- 18:2b5ed529ab37
- Parent:
- 17:0739cb2f1930
- Child:
- 19:bf5f5ea4e762
File content as of revision 18:2b5ed529ab37:
#include "SimpleShell.h" #include <ctype.h> #include <string> #define ESC 0x1b #define UP 0x41 #define DOWN 0x42 #define RIGHT 0x43 #define LEFT 0x44 #define HOME 0x31 #define INS 0x32 #define DEL 0x33 #define PGUP 0x35 #define PGDN 0x36 #define TAIL 0x7e char *SimpleShell::canon(char *path) { static char result[MAXBUF]; if (path[0] != '/') { strncpy(result, _cwd, MAXBUF); strcat(result, "/"); } strcat(result, path); return result; } SimpleShell::SimpleShell() { lookupEnd = 0; // Built-in shell commands attach(callback(this, &SimpleShell::help), "help"); attach(callback(this, &SimpleShell::pwd), "pwd"); attach(callback(this, &SimpleShell::cat), "cat"); attach(callback(this, &SimpleShell::cd), "cd"); attach(callback(this, &SimpleShell::ls), "ls"); } void SimpleShell::help(int argc, char **argv) { printf("Available commands: "); for (int i=0; i < lookupEnd; i++) { printf("%s ", lookup[i].command); } printf("\n\n"); } void SimpleShell::cd(int argc, char **argv) { if (argc == 2) { strncpy(_cwd, argv[1], MAXBUF); } else { puts("usage: cd directory"); } return; } void SimpleShell::pwd(int argc, char **argv) { puts(_cwd); return; } void SimpleShell::ls(int argc, char **argv) { DIR *d; struct dirent *p; char *path; if (argc == 1) { path = _cwd; } else if (argc == 2) { path = argv[1]; } else { puts("usage: ls [directory]"); return; } int cols=0; if ((d = opendir(path)) != NULL) { while ((p = readdir(d)) != NULL) { if (p->d_name && p->d_name[0] != 0xff) { if (cols++ > 3) { putc('\n', stdout); cols = 0; } printf("%-15s ", p->d_name); } } putc('\n', stdout); if (cols < 3) putc('\n', stdout); closedir(d); } else { puts(path); puts(": No such directory\n"); } return; } void SimpleShell::cat(int argc, char **argv) { FILE *fp; //int status=0; char *buf = new char[MAXBUF]; for (int i=1; i < argc; i++) { //resolveDirectory(path, arg); if ((fp = fopen(canon(argv[i]), "r")) != NULL) { while (!feof(fp)) { fgets(buf, MAXBUF-1, fp); fputs(buf, stdout); } fclose(fp); } else { fputs(argv[i], stdout); fputs(": No such file\n", stdout); //status = 1; } } delete[] buf; return; } void SimpleShell::run() { bool done=false; callback_t cb; //int status; // TODO implement command status return std::string x; // Set current working directory strncpy(_cwd, "/etc", MAXBUF); printf("Type help for assistance.\n"); help(0, NULL); while (!done) { printPrompt(); readCommand(); if (argv[0]) { // skip blank command if (cb = findCommand()) { cb.call(argc, argv); } else { printf("command <%s> not found\n", argv[0]); } } } puts("exiting shell\n"); return; } void SimpleShell::attach(callback_t cb, char *command) { if (lookupEnd < MAXLOOKUP) { lookup[lookupEnd].cb = cb; lookup[lookupEnd].command = command; lookupEnd++; } return; } SimpleShell::callback_t SimpleShell::findCommand() { SimpleShell::callback_t cb=NULL; for (int i=0; i < lookupEnd; i++) { if (strncmp(argv[0], lookup[i].command, MAXBUF) == 0) { cb = lookup[i].cb; break; } } return cb; } void SimpleShell::printPrompt() { fputc('(', stdout); fputs(_cwd, stdout); fputs(")# ", stdout); return; } void SimpleShell::readCommand() { int i=0; char c; bool done = false; static char cmd[MAXBUF]; memset(cmd, 0, MAXBUF); do { cmd[i] = 0; c = fgetc(stdin); if (c == '\r') { // if return is hit, we're done, don't add \r to cmd done = true; } else if (c == ESC) { // keyboard escape codes (arrow keys, etc) int c2 = getchar(); int c3 = getchar(); if (c2 == 0x4f && c3 == 0x46) { printf("<END>"); } else if (c2 == 0x5b) { if (c3 == UP) { printf("<UP>"); } else if (c3 == DOWN) { printf("<DOWN>"); } else if (c3 == RIGHT) { printf("<RIGHT>"); } else if (c3 == LEFT) { printf("<LEFT>"); } else if (c3 == HOME || c3 == INS || c3 == DEL || c3 == PGUP || c3 == PGDN) { char c4 = getchar(); if (c4 == TAIL) { if (c4 == HOME) { printf("<HOME>"); } else if (c4 == INS) { printf("<INS>"); } else if (c4 == DEL) { printf("<DEL>"); } else if (c4 == PGUP) { printf("<PGUP>"); } else if (c4 == PGDN) { printf("<PGDN>"); }//if }//if }//if }//if //printf("\n"); } else if (i < MAXBUF-1) { if (c == 0x7f || c == '\b') { // backspace or delete if (i > 0) { // if we're at the beginning, do nothing i--; fputs("\b \b", stdout); } } else { if (isprint(c)) fputc(c, stdout); cmd[i++] = c; } } } while (!done); fputc('\n', stdout); // remove leading/trailing whitespace char *s = cmd; while (isspace(*s)) { s++; } for (int j=i; j >= 0 && isspace(cmd[j]); j--) { cmd[j] = '\0'; } // split into command and arguments argc = 0; char *t; for (int i=0; i < MAXARGS; i++) { argv[i] = NULL; } t = strtok(s, " "); while (t && argc < 10) { argv[argc++] = t; t = strtok(NULL, " "); } return; }