1 /* gawkmisc.c --- miscellaneous gawk routines that are OS specific.
2
3 Copyright (C) 1986, 1988, 1989, 1991 - 1998, 2001 - 2004, 2011, 2021,
4 the Free Software Foundation, Inc.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
19
20 #ifdef __CYGWIN__
21 #include <stdio.h>
22 #include <windows.h>
23 #include <sys/cygwin.h>
24 #include <io.h>
25 #endif
26
27 const char quote = '\'';
28 const char *defpath = DEFPATH;
29 const char *deflibpath = DEFLIBPATH;
30 const char envsep = ':';
31
32 #ifndef INVALID_HANDLE
33 /* FIXME: is this value for INVALID_HANDLE correct? */
34 #define INVALID_HANDLE -1
35 #endif
36
37 /* gawk_name --- pull out the "gawk" part from how the OS called us */
38
39 const char *
gawk_name(const char * filespec)40 gawk_name(const char *filespec)
41 {
42 const char *p;
43
44 /* "path/name" -> "name" */
45 p = strrchr(filespec, '/');
46 return (p == NULL ? (char *) filespec : p + 1);
47 }
48
49 /* os_arg_fixup --- fixup the command line */
50
51 void
os_arg_fixup(int * argcp,char *** argvp)52 os_arg_fixup(int *argcp, char ***argvp)
53 {
54 /* no-op */
55 return;
56 }
57
58 /* os_devopen --- open special per-OS devices */
59
60 int
os_devopen(const char * name,int flag)61 os_devopen(const char *name, int flag)
62 {
63 /* no-op */
64 return INVALID_HANDLE;
65 }
66
67 /* optimal_bufsize --- determine optimal buffer size */
68
69 /*
70 * Enhance this for debugging purposes, as follows:
71 *
72 * Always stat the file, stat buffer is used by higher-level code.
73 *
74 * if (AWKBUFSIZE == "exact")
75 * return the file size
76 * else if (AWKBUFSIZE == a number)
77 * always return that number
78 * else
79 * if the size is < default_blocksize
80 * return the size
81 * else
82 * return default_blocksize
83 * end if
84 * endif
85 *
86 * Hair comes in an effort to only deal with AWKBUFSIZE
87 * once, the first time this routine is called, instead of
88 * every time. Performance, dontyaknow.
89 */
90
91 size_t
optimal_bufsize(int fd,struct stat * stb)92 optimal_bufsize(int fd, struct stat *stb)
93 {
94 char *val;
95 static size_t env_val = 0;
96 static bool first = true;
97 static bool exact = false;
98
99 /* force all members to zero in case OS doesn't use all of them. */
100 memset(stb, '\0', sizeof(struct stat));
101
102 /* always stat, in case stb is used by higher level code. */
103 if (fstat(fd, stb) == -1)
104 fatal("can't stat fd %d (%s)", fd, strerror(errno));
105
106 if (first) {
107 first = false;
108
109 if ((val = getenv("AWKBUFSIZE")) != NULL) {
110 if (strcmp(val, "exact") == 0)
111 exact = true;
112 else if (isdigit((unsigned char) *val)) {
113 for (; *val && isdigit((unsigned char) *val); val++)
114 env_val = (env_val * 10) + *val - '0';
115
116 return env_val;
117 }
118 }
119 } else if (! exact && env_val > 0)
120 return env_val;
121 /* else
122 fall through */
123
124 /*
125 * System V.n, n < 4, doesn't have the file system block size in the
126 * stat structure. So we have to make some sort of reasonable
127 * guess. We use stdio's BUFSIZ, since that is what it was
128 * meant for in the first place.
129 */
130 #ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
131 #define DEFBLKSIZE (stb->st_blksize > 0 ? stb->st_blksize : BUFSIZ)
132 #else
133 #define DEFBLKSIZE BUFSIZ
134 #endif
135
136 if (S_ISREG(stb->st_mode) /* regular file */
137 && 0 < stb->st_size /* non-zero size */
138 && (stb->st_size < DEFBLKSIZE /* small file */
139 || exact)) /* or debugging */
140 return stb->st_size; /* use file size */
141
142 return DEFBLKSIZE;
143 }
144
145 /* ispath --- return true if path has directory components */
146
147 int
ispath(const char * file)148 ispath(const char *file)
149 {
150 return (strchr(file, '/') != NULL);
151 }
152
153 /* isdirpunct --- return true if char is a directory separator */
154
155 int
isdirpunct(int c)156 isdirpunct(int c)
157 {
158 return (c == '/');
159 }
160
161 /* os_close_on_exec --- set close on exec flag, print warning if fails */
162
163 void
os_close_on_exec(int fd,const char * name,const char * what,const char * dir)164 os_close_on_exec(int fd, const char *name, const char *what, const char *dir)
165 {
166 int curflags = 0;
167
168 if (fd <= 2) /* sanity */
169 return;
170
171 /*
172 * Per POSIX, use Read/Modify/Write - get the flags,
173 * add FD_CLOEXEC, set the flags back.
174 */
175
176 if ((curflags = fcntl(fd, F_GETFD)) < 0) {
177 warning(_("%s %s `%s': could not get fd flags: (fcntl F_GETFD: %s)"),
178 what, dir, name, strerror(errno));
179 return;
180 }
181
182 #ifndef FD_CLOEXEC
183 #define FD_CLOEXEC 1
184 #endif
185
186 curflags |= FD_CLOEXEC;
187
188 if (fcntl(fd, F_SETFD, curflags) < 0)
189 warning(_("%s %s `%s': could not set close-on-exec: (fcntl F_SETFD: %s)"),
190 what, dir, name, strerror(errno));
191 }
192
193 /* os_isdir --- is this an fd on a directory? */
194
195 #if ! defined(S_ISDIR) && defined(S_IFDIR)
196 #define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
197 #endif
198
199 int
os_isdir(int fd)200 os_isdir(int fd)
201 {
202 struct stat sbuf;
203
204 return (fstat(fd, &sbuf) == 0 && S_ISDIR(sbuf.st_mode));
205 }
206
207 /* os_isreadable --- fd can be read from */
208
209 int
os_isreadable(const awk_input_buf_t * iobuf,bool * isdir)210 os_isreadable(const awk_input_buf_t *iobuf, bool *isdir)
211 {
212 *isdir = false;
213
214 if (iobuf->fd == INVALID_HANDLE)
215 return false;
216
217 switch (iobuf->sbuf.st_mode & S_IFMT) {
218 case S_IFREG:
219 case S_IFCHR: /* ttys, /dev/null, .. */
220 #ifdef S_IFSOCK
221 case S_IFSOCK:
222 #endif
223 #ifdef S_IFIFO
224 case S_IFIFO:
225 #endif
226 return true;
227 case S_IFDIR:
228 *isdir = true;
229 /* fall through */
230 default:
231 return false;
232 }
233 }
234
235 /* os_is_setuid --- true if running setuid root */
236
237 int
os_is_setuid()238 os_is_setuid()
239 {
240 long uid, euid;
241
242 uid = getuid();
243 euid = geteuid();
244
245 return (euid == 0 && euid != uid);
246 }
247
248 /* os_setbinmode --- set binary mode on file */
249
250 int
os_setbinmode(int fd,int mode)251 os_setbinmode(int fd, int mode)
252 {
253 #ifdef __CYGWIN__
254 setmode (fd, mode);
255 #endif
256 return 0;
257 }
258
259 /* os_restore_mode --- restore the original mode of the console device */
260
261 void
os_restore_mode(int fd)262 os_restore_mode(int fd)
263 {
264 /* no-op */
265 return;
266 }
267
268 /* os_isatty --- return true if fd is a tty */
269
270 int
os_isatty(int fd)271 os_isatty(int fd)
272 {
273 return isatty(fd);
274 }
275
276 /* files_are_same --- return true if files are identical */
277
278 int
files_are_same(char * path,SRCFILE * src)279 files_are_same(char *path, SRCFILE *src)
280 {
281 struct stat st;
282
283 return (stat(path, & st) == 0
284 && st.st_dev == src->sbuf.st_dev
285 && st.st_ino == src->sbuf.st_ino);
286 }
287
288 void
init_sockets(void)289 init_sockets(void)
290 {
291 }
292
293 // For MSYS, restore behavior of working in text mode.
294 #ifdef __MSYS__
295 void
cygwin_premain0(int argc,char ** argv,struct per_process * myself)296 cygwin_premain0(int argc, char **argv, struct per_process *myself)
297 {
298 static struct __cygwin_perfile pf[] = {
299 { "", O_RDONLY | O_TEXT },
300 /*{ "", O_WRONLY | O_BINARY },*/
301 { NULL, 0 }
302 };
303 cygwin_internal(CW_PERFILE, pf);
304 }
305
306 void
cygwin_premain2(int argc,char ** argv,struct per_process * myself)307 cygwin_premain2(int argc, char **argv, struct per_process *myself)
308 {
309 setmode(fileno (stdin), O_TEXT);
310 }
311 #endif
312