1 /* $OpenBSD: cmd-show-environment.c,v 1.28 2021/08/21 10:22:39 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 
21 #include <stdlib.h>
22 #include <string.h>
23 
24 #include "tmux.h"
25 
26 /*
27  * Show environment.
28  */
29 
30 static enum cmd_retval	cmd_show_environment_exec(struct cmd *,
31 			    struct cmdq_item *);
32 
33 static char	*cmd_show_environment_escape(struct environ_entry *);
34 static void	 cmd_show_environment_print(struct cmd *, struct cmdq_item *,
35 		     struct environ_entry *);
36 
37 const struct cmd_entry cmd_show_environment_entry = {
38 	.name = "show-environment",
39 	.alias = "showenv",
40 
41 	.args = { "hgst:", 0, 1, NULL },
42 	.usage = "[-hgs] " CMD_TARGET_SESSION_USAGE " [name]",
43 
44 	.target = { 't', CMD_FIND_SESSION, CMD_FIND_CANFAIL },
45 
46 	.flags = CMD_AFTERHOOK,
47 	.exec = cmd_show_environment_exec
48 };
49 
50 static char *
51 cmd_show_environment_escape(struct environ_entry *envent)
52 {
53 	const char	*value = envent->value;
54 	char		 c, *out, *ret;
55 
56 	out = ret = xmalloc(strlen(value) * 2 + 1); /* at most twice the size */
57 	while ((c = *value++) != '\0') {
58 		/* POSIX interprets $ ` " and \ in double quotes. */
59 		if (c == '$' || c == '`' || c == '"' || c == '\\')
60 			*out++ = '\\';
61 		*out++ = c;
62 	}
63 	*out = '\0';
64 
65 	return (ret);
66 }
67 
68 static void
69 cmd_show_environment_print(struct cmd *self, struct cmdq_item *item,
70     struct environ_entry *envent)
71 {
72 	struct args	*args = cmd_get_args(self);
73 	char		*escaped;
74 
75 	if (!args_has(args, 'h') && (envent->flags & ENVIRON_HIDDEN))
76 		return;
77 	if (args_has(args, 'h') && (~envent->flags & ENVIRON_HIDDEN))
78 		return;
79 
80 	if (!args_has(args, 's')) {
81 		if (envent->value != NULL)
82 			cmdq_print(item, "%s=%s", envent->name, envent->value);
83 		else
84 			cmdq_print(item, "-%s", envent->name);
85 		return;
86 	}
87 
88 	if (envent->value != NULL) {
89 		escaped = cmd_show_environment_escape(envent);
90 		cmdq_print(item, "%s=\"%s\"; export %s;", envent->name, escaped,
91 		    envent->name);
92 		free(escaped);
93 	} else
94 		cmdq_print(item, "unset %s;", envent->name);
95 }
96 
97 static enum cmd_retval
98 cmd_show_environment_exec(struct cmd *self, struct cmdq_item *item)
99 {
100 	struct args		*args = cmd_get_args(self);
101 	struct cmd_find_state	*target = cmdq_get_target(item);
102 	struct environ		*env;
103 	struct environ_entry	*envent;
104 	const char		*tflag, *name = args_string(args, 0);
105 
106 	if ((tflag = args_get(args, 't')) != NULL) {
107 		if (target->s == NULL) {
108 			cmdq_error(item, "no such session: %s", tflag);
109 			return (CMD_RETURN_ERROR);
110 		}
111 	}
112 
113 	if (args_has(args, 'g'))
114 		env = global_environ;
115 	else {
116 		if (target->s == NULL) {
117 			tflag = args_get(args, 't');
118 			if (tflag != NULL)
119 				cmdq_error(item, "no such session: %s", tflag);
120 			else
121 				cmdq_error(item, "no current session");
122 			return (CMD_RETURN_ERROR);
123 		}
124 		env = target->s->environ;
125 	}
126 
127 	if (name != NULL) {
128 		envent = environ_find(env, name);
129 		if (envent == NULL) {
130 			cmdq_error(item, "unknown variable: %s", name);
131 			return (CMD_RETURN_ERROR);
132 		}
133 		cmd_show_environment_print(self, item, envent);
134 		return (CMD_RETURN_NORMAL);
135 	}
136 
137 	envent = environ_first(env);
138 	while (envent != NULL) {
139 		cmd_show_environment_print(self, item, envent);
140 		envent = environ_next(envent);
141 	}
142 	return (CMD_RETURN_NORMAL);
143 }
144