1#include "cache.h"
2#include "run-command.h"
3#include "exec_cmd.h"
4
5static inline void close_pair(int fd[2])
6{
7 close(fd[0]);
8 close(fd[1]);
9}
10
11static inline void dup_devnull(int to)
12{
13 int fd = open("/dev/null", O_RDWR);
14 dup2(fd, to);
15 close(fd);
16}
17
18int start_command(struct child_process *cmd)
19{
20 int need_in, need_out, need_err;
21 int fdin[2], fdout[2], fderr[2];
22
23
24
25
26
27
28 need_in = !cmd->no_stdin && cmd->in < 0;
29 if (need_in) {
30 if (pipe(fdin) < 0) {
31 if (cmd->out > 0)
32 close(cmd->out);
33 return -ERR_RUN_COMMAND_PIPE;
34 }
35 cmd->in = fdin[1];
36 }
37
38 need_out = !cmd->no_stdout
39 && !cmd->stdout_to_stderr
40 && cmd->out < 0;
41 if (need_out) {
42 if (pipe(fdout) < 0) {
43 if (need_in)
44 close_pair(fdin);
45 else if (cmd->in)
46 close(cmd->in);
47 return -ERR_RUN_COMMAND_PIPE;
48 }
49 cmd->out = fdout[0];
50 }
51
52 need_err = !cmd->no_stderr && cmd->err < 0;
53 if (need_err) {
54 if (pipe(fderr) < 0) {
55 if (need_in)
56 close_pair(fdin);
57 else if (cmd->in)
58 close(cmd->in);
59 if (need_out)
60 close_pair(fdout);
61 else if (cmd->out)
62 close(cmd->out);
63 return -ERR_RUN_COMMAND_PIPE;
64 }
65 cmd->err = fderr[0];
66 }
67
68 fflush(NULL);
69 cmd->pid = fork();
70 if (!cmd->pid) {
71 if (cmd->no_stdin)
72 dup_devnull(0);
73 else if (need_in) {
74 dup2(fdin[0], 0);
75 close_pair(fdin);
76 } else if (cmd->in) {
77 dup2(cmd->in, 0);
78 close(cmd->in);
79 }
80
81 if (cmd->no_stderr)
82 dup_devnull(2);
83 else if (need_err) {
84 dup2(fderr[1], 2);
85 close_pair(fderr);
86 }
87
88 if (cmd->no_stdout)
89 dup_devnull(1);
90 else if (cmd->stdout_to_stderr)
91 dup2(2, 1);
92 else if (need_out) {
93 dup2(fdout[1], 1);
94 close_pair(fdout);
95 } else if (cmd->out > 1) {
96 dup2(cmd->out, 1);
97 close(cmd->out);
98 }
99
100 if (cmd->dir && chdir(cmd->dir))
101 die("exec %s: cd to %s failed (%s)", cmd->argv[0],
102 cmd->dir, strerror(errno));
103 if (cmd->env) {
104 for (; *cmd->env; cmd->env++) {
105 if (strchr(*cmd->env, '='))
106 putenv((char*)*cmd->env);
107 else
108 unsetenv(*cmd->env);
109 }
110 }
111 if (cmd->preexec_cb)
112 cmd->preexec_cb();
113 if (cmd->perf_cmd) {
114 execv_perf_cmd(cmd->argv);
115 } else {
116 execvp(cmd->argv[0], (char *const*) cmd->argv);
117 }
118 exit(127);
119 }
120
121 if (cmd->pid < 0) {
122 int err = errno;
123 if (need_in)
124 close_pair(fdin);
125 else if (cmd->in)
126 close(cmd->in);
127 if (need_out)
128 close_pair(fdout);
129 else if (cmd->out)
130 close(cmd->out);
131 if (need_err)
132 close_pair(fderr);
133 return err == ENOENT ?
134 -ERR_RUN_COMMAND_EXEC :
135 -ERR_RUN_COMMAND_FORK;
136 }
137
138 if (need_in)
139 close(fdin[0]);
140 else if (cmd->in)
141 close(cmd->in);
142
143 if (need_out)
144 close(fdout[1]);
145 else if (cmd->out)
146 close(cmd->out);
147
148 if (need_err)
149 close(fderr[1]);
150
151 return 0;
152}
153
154static int wait_or_whine(pid_t pid)
155{
156 for (;;) {
157 int status, code;
158 pid_t waiting = waitpid(pid, &status, 0);
159
160 if (waiting < 0) {
161 if (errno == EINTR)
162 continue;
163 error("waitpid failed (%s)", strerror(errno));
164 return -ERR_RUN_COMMAND_WAITPID;
165 }
166 if (waiting != pid)
167 return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
168 if (WIFSIGNALED(status))
169 return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
170
171 if (!WIFEXITED(status))
172 return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
173 code = WEXITSTATUS(status);
174 switch (code) {
175 case 127:
176 return -ERR_RUN_COMMAND_EXEC;
177 case 0:
178 return 0;
179 default:
180 return -code;
181 }
182 }
183}
184
185int finish_command(struct child_process *cmd)
186{
187 return wait_or_whine(cmd->pid);
188}
189
190int run_command(struct child_process *cmd)
191{
192 int code = start_command(cmd);
193 if (code)
194 return code;
195 return finish_command(cmd);
196}
197
198static void prepare_run_command_v_opt(struct child_process *cmd,
199 const char **argv,
200 int opt)
201{
202 memset(cmd, 0, sizeof(*cmd));
203 cmd->argv = argv;
204 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
205 cmd->perf_cmd = opt & RUN_PERF_CMD ? 1 : 0;
206 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
207}
208
209int run_command_v_opt(const char **argv, int opt)
210{
211 struct child_process cmd;
212 prepare_run_command_v_opt(&cmd, argv, opt);
213 return run_command(&cmd);
214}
215
