blob: 3be64eec7a9b989ade0d9b40a98b920c133c7284 [file] [log] [blame]
Rob Landley02add9e2006-09-05 03:22:19 +00001/* vi: set ts=4 :
Denis Vlasenkof7996f32007-01-11 17:20:00 +00002 *
Rob Landley02add9e2006-09-05 03:22:19 +00003 * bbsh - busybox shell
4 *
5 * Copyright 2006 Rob Landley <rob@landley.net>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9
Rob Landley3476ad62006-09-08 16:59:08 +000010// A section of code that gets repeatedly or conditionally executed is stored
11// as a string and parsed each time it's run.
12
13
14
15// Wheee, debugging.
16
17// Terminal control
18#define ENABLE_BBSH_TTY 0
19
20// &, fg, bg, jobs. (ctrl-z with tty.)
21#define ENABLE_BBSH_JOBCTL 0
22
23// Flow control (if, while, for, functions { })
24#define ENABLE_BBSH_FLOWCTL 0
25
26#define ENABLE_BBSH_ENVVARS 0 // Environment variable support
27
28// Local and synthetic variables, fancy prompts, set, $?, etc.
29#define ENABLE_BBSH_LOCALVARS 0
30
31// Pipes and redirects: | > < >> << && || & () ;
32#define ENABLE_BBSH_PIPES 0
33
34/* Fun:
35
36 echo `echo hello#comment " woot` and more
37*/
Rob Landley02add9e2006-09-05 03:22:19 +000038
Denis Vlasenkob6adbf12007-05-26 19:00:18 +000039#include "libbb.h"
Rob Landley02add9e2006-09-05 03:22:19 +000040
Rob Landley3476ad62006-09-08 16:59:08 +000041// A single executable, its arguments, and other information we know about it.
42#define BBSH_FLAG_EXIT 1
43#define BBSH_FLAG_SUSPEND 2
44#define BBSH_FLAG_PIPE 4
45#define BBSH_FLAG_AND 8
46#define BBSH_FLAG_OR 16
47#define BBSH_FLAG_AMP 32
48#define BBSH_FLAG_SEMI 64
49#define BBSH_FLAG_PAREN 128
50
51// What we know about a single process.
52struct command {
53 struct command *next;
Denis Vlasenkof7996f32007-01-11 17:20:00 +000054 int flags; // exit, suspend, && ||
Rob Landley3476ad62006-09-08 16:59:08 +000055 int pid; // pid (or exit code)
56 int argc;
57 char *argv[0];
58};
59
60// A collection of processes piped into/waiting on each other.
61struct pipeline {
62 struct pipeline *next;
63 int job_id;
64 struct command *cmd;
65 char *cmdline;
66 int cmdlinelen;
67};
68
69static void free_list(void *list, void (*freeit)(void *data))
Rob Landley02add9e2006-09-05 03:22:19 +000070{
Denis Vlasenko51742f42007-04-12 00:32:05 +000071 while (list) {
Rob Landley3476ad62006-09-08 16:59:08 +000072 void **next = (void **)list;
73 void *list_next = *next;
74 freeit(list);
75 free(list);
76 list = list_next;
77 }
78}
79
80// Parse one word from the command line, appending one or more argv[] entries
81// to struct command. Handles environment variable substitution and
82// substrings. Returns pointer to next used byte, or NULL if it
83// hit an ending token.
84static char *parse_word(char *start, struct command **cmd)
85{
86 char *end;
87
88 // Detect end of line (and truncate line at comment)
89 if (ENABLE_BBSH_PIPES && strchr("><&|(;", *start)) return 0;
90
91 // Grab next word. (Add dequote and envvar logic here)
92 end = start;
Bernhard Reutner-Fischerde17ece2007-04-10 09:38:35 +000093 end = skip_non_whitespace(end);
Rob Landley3476ad62006-09-08 16:59:08 +000094 (*cmd)->argv[(*cmd)->argc++] = xstrndup(start, end-start);
95
96 // Allocate more space if there's no room for NULL terminator.
97
98 if (!((*cmd)->argc & 7))
99 *cmd = xrealloc(*cmd,
100 sizeof(struct command) + ((*cmd)->argc+8)*sizeof(char *));
101 (*cmd)->argv[(*cmd)->argc] = 0;
102 return end;
103}
104
105// Parse a line of text into a pipeline.
106// Returns a pointer to the next line.
107
Rob Landleyef081842006-09-08 17:21:19 +0000108static char *parse_pipeline(char *cmdline, struct pipeline *line)
Rob Landley3476ad62006-09-08 16:59:08 +0000109{
Rob Landleyef081842006-09-08 17:21:19 +0000110 struct command **cmd = &(line->cmd);
111 char *start = line->cmdline = cmdline;
Rob Landley3476ad62006-09-08 16:59:08 +0000112
113 if (!cmdline) return 0;
114
Rob Landleyef081842006-09-08 17:21:19 +0000115 if (ENABLE_BBSH_JOBCTL) line->cmdline = cmdline;
Rob Landley02add9e2006-09-05 03:22:19 +0000116
117 // Parse command into argv[]
118 for (;;) {
119 char *end;
120
Rob Landley3476ad62006-09-08 16:59:08 +0000121 // Skip leading whitespace and detect end of line.
Denis Vlasenkod18a3a22006-10-25 12:46:03 +0000122 start = skip_whitespace(start);
Rob Landley3476ad62006-09-08 16:59:08 +0000123 if (!*start || *start=='#') {
Rob Landleyef081842006-09-08 17:21:19 +0000124 if (ENABLE_BBSH_JOBCTL) line->cmdlinelen = start-cmdline;
Rob Landley3476ad62006-09-08 16:59:08 +0000125 return 0;
126 }
Rob Landley02add9e2006-09-05 03:22:19 +0000127
Denis Vlasenkof7996f32007-01-11 17:20:00 +0000128 // Allocate next command structure if necessary
Rob Landley3476ad62006-09-08 16:59:08 +0000129 if (!*cmd) *cmd = xzalloc(sizeof(struct command)+8*sizeof(char *));
Denis Vlasenkof7996f32007-01-11 17:20:00 +0000130
Rob Landley3476ad62006-09-08 16:59:08 +0000131 // Parse next argument and add the results to argv[]
132 end = parse_word(start, cmd);
133
134 // If we hit the end of this command, how did it end?
135 if (!end) {
136 if (ENABLE_BBSH_PIPES && *start) {
137 if (*start==';') {
138 start++;
139 break;
140 }
Denis Vlasenkof7996f32007-01-11 17:20:00 +0000141 // handle | & < > >> << || &&
Rob Landley3476ad62006-09-08 16:59:08 +0000142 }
143 break;
144 }
145 start = end;
Rob Landley02add9e2006-09-05 03:22:19 +0000146 }
Rob Landley02add9e2006-09-05 03:22:19 +0000147
Rob Landleyef081842006-09-08 17:21:19 +0000148 if (ENABLE_BBSH_JOBCTL) line->cmdlinelen = start-cmdline;
Rob Landley3476ad62006-09-08 16:59:08 +0000149
150 return start;
151}
152
153// Execute the commands in a pipeline
Rob Landleyef081842006-09-08 17:21:19 +0000154static int run_pipeline(struct pipeline *line)
Rob Landley3476ad62006-09-08 16:59:08 +0000155{
Rob Landleyef081842006-09-08 17:21:19 +0000156 struct command *cmd = line->cmd;
Rob Landley3476ad62006-09-08 16:59:08 +0000157 if (!cmd || !cmd->argc) return 0;
158
159 // Handle local commands. This is totally fake and plastic.
160 if (cmd->argc==2 && !strcmp(cmd->argv[0],"cd"))
161 chdir(cmd->argv[1]);
Denis Vlasenko51742f42007-04-12 00:32:05 +0000162 else if (!strcmp(cmd->argv[0],"exit"))
Denis Vlasenkof7996f32007-01-11 17:20:00 +0000163 exit(cmd->argc>1 ? atoi(cmd->argv[1]) : 0);
Rob Landley02add9e2006-09-05 03:22:19 +0000164 else {
165 int status;
166 pid_t pid=fork();
Denis Vlasenko51742f42007-04-12 00:32:05 +0000167 if (!pid) {
Denis Vlasenkoe4f2d062007-04-11 17:03:19 +0000168 run_applet_and_exit(cmd->argv[0],cmd->argc,cmd->argv);
Rob Landley3476ad62006-09-08 16:59:08 +0000169 execvp(cmd->argv[0],cmd->argv);
Denis Vlasenkof5d8c902008-06-26 14:32:57 +0000170 printf("No %s", cmd->argv[0]);
Bernhard Reutner-Fischer636a1f82008-05-19 09:29:47 +0000171 exit(EXIT_FAILURE);
Rob Landley02add9e2006-09-05 03:22:19 +0000172 } else waitpid(pid, &status, 0);
173 }
Rob Landley02add9e2006-09-05 03:22:19 +0000174
175 return 0;
176}
177
Rob Landley3476ad62006-09-08 16:59:08 +0000178static void free_cmd(void *data)
179{
180 struct command *cmd=(struct command *)data;
181
Denis Vlasenko51742f42007-04-12 00:32:05 +0000182 while (cmd->argc) free(cmd->argv[--cmd->argc]);
Rob Landley3476ad62006-09-08 16:59:08 +0000183}
184
185
186static void handle(char *command)
187{
Rob Landleyef081842006-09-08 17:21:19 +0000188 struct pipeline line;
Rob Landley3476ad62006-09-08 16:59:08 +0000189 char *start = command;
190
191 for (;;) {
Rob Landleyef081842006-09-08 17:21:19 +0000192 memset(&line,0,sizeof(struct pipeline));
193 start = parse_pipeline(start, &line);
194 if (!line.cmd) break;
Rob Landley3476ad62006-09-08 16:59:08 +0000195
Rob Landleyef081842006-09-08 17:21:19 +0000196 run_pipeline(&line);
197 free_list(line.cmd, free_cmd);
Rob Landley3476ad62006-09-08 16:59:08 +0000198 }
199}
200
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +0000201int bbsh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Bernhard Reutner-Fischerfebe3c42007-04-04 20:52:03 +0000202int bbsh_main(int argc, char **argv)
Rob Landley02add9e2006-09-05 03:22:19 +0000203{
204 char *command=NULL;
205 FILE *f;
206
Denis Vlasenkofe7cd642007-08-18 15:32:12 +0000207 getopt32(argv, "c:", &command);
Rob Landley02add9e2006-09-05 03:22:19 +0000208
209 f = argv[optind] ? xfopen(argv[optind],"r") : NULL;
210 if (command) handle(command);
211 else {
212 unsigned cmdlen=0;
213 for (;;) {
Denis Vlasenko51742f42007-04-12 00:32:05 +0000214 if (!f) putchar('$');
215 if (1 > getline(&command, &cmdlen,f ? : stdin)) break;
Rob Landley3476ad62006-09-08 16:59:08 +0000216
Rob Landley02add9e2006-09-05 03:22:19 +0000217 handle(command);
218 }
219 if (ENABLE_FEATURE_CLEAN_UP) free(command);
220 }
Denis Vlasenkof7996f32007-01-11 17:20:00 +0000221
Rob Landley02add9e2006-09-05 03:22:19 +0000222 return 1;
223}