1 /*****************************************************************************
2 
3 gifinto - save GIF on stdin to file if size over set threshold
4 
5 SPDX-License-Identifier: MIT
6 
7 *****************************************************************************/
8 
9 #include <fcntl.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <ctype.h>
13 #include <string.h>
14 #include <stdbool.h>
15 
16 #ifdef _WIN32
17 #include <io.h>
18 #else
19 #include <unistd.h>
20 #endif /* _WIN32 */
21 
22 #include "gif_lib.h"
23 #include "getarg.h"
24 
25 #define PROGRAM_NAME	"gifinto"
26 
27 #define STRLEN		512
28 
29 #define DEFAULT_MIN_FILE_SIZE	14     /* More than GIF stamp + screen desc. */
30 #define	DEFAULT_OUT_NAME	"GifInto.Gif"
31 #define DEFAULT_TMP_NAME	"TempInto.XXXXXX"
32 
33 static char
34     *VersionStr =
35 	PROGRAM_NAME
36 	VERSION_COOKIE
37 	"	Gershon Elber,	"
38 	__DATE__ ",   " __TIME__ "\n"
39 	"(C) Copyright 1989 Gershon Elber.\n";
40 static char
41     *CtrlStr =
42 	PROGRAM_NAME
43 	" v%- s%-MinFileSize!d h%- GifFile!*s";
44 
45 static int
46     MinFileSize = DEFAULT_MIN_FILE_SIZE;
47 
48 #ifdef _WIN32
49 #include <errno.h>
50 #include <sys/stat.h>
51 int
mkstemp(char * tpl)52 mkstemp(char *tpl)
53 {
54   int fd = -1;
55   char *p;
56   int e = errno;
57 
58   errno = 0;
59   p = _mktemp(tpl);
60   if (*p && errno == 0)
61     {
62       errno = e;
63       fd = _open(p, _O_RDWR | _O_CREAT | _O_EXCL | _O_BINARY,
64 		 _S_IREAD | _S_IWRITE);
65     }
66   return fd;
67 }
68 #endif
69 
70 /******************************************************************************
71  This is simply: read until EOF, then close the output, test its length, and
72  if non zero then rename it.
73 ******************************************************************************/
main(int argc,char ** argv)74 int main(int argc, char **argv)
75 {
76     int FD;
77     int	NumFiles;
78     bool Error, MinSizeFlag = false, HelpFlag = false;
79     char **FileName = NULL, FoutTmpName[STRLEN+1], FullPath[STRLEN+1], *p;
80     FILE *Fin, *Fout;
81 
82     if ((Error = GAGetArgs(argc, argv, CtrlStr, &GifNoisyPrint,
83 		&MinSizeFlag, &MinFileSize, &HelpFlag,
84 		&NumFiles, &FileName)) != false ||
85 		(NumFiles > 1 && !HelpFlag)) {
86 	if (Error)
87 	    GAPrintErrMsg(Error);
88 	else if (NumFiles != 1)
89 	    GIF_MESSAGE("Error in command line parsing - one GIF file please.");
90 	GAPrintHowTo(CtrlStr);
91 	exit(EXIT_FAILURE);
92     }
93 
94     if (HelpFlag) {
95 	(void)fprintf(stderr, VersionStr, GIFLIB_MAJOR, GIFLIB_MINOR);
96 	GAPrintHowTo(CtrlStr);
97 	exit(EXIT_SUCCESS);
98     }
99 
100     /* Open the stdin in binary mode and increase its buffer size: */
101 #ifdef _WIN32
102     _setmode(0, O_BINARY);		  /* Make sure it is in binary mode. */
103 #endif
104 
105     Fin = fdopen(0, "rb");   /* Make it into a stream: */
106 
107     if (Fin == NULL)
108     {
109         GIF_EXIT("Failed to open input.");
110     }
111 
112     /* Isolate the directory where our destination is, and set tmp file name */
113     /* in the very same directory. This code is isecure because it creates   */
114     /* predictable names, but it's not worth the effort and risk to fix.     */
115     if ( *FileName == NULL ) GIF_EXIT("No valid Filename given.");
116     if ( strlen(*FileName) > STRLEN-1 ) GIF_EXIT("Filename too long.");
117     memset(FullPath, '\0', sizeof(FullPath));
118     strncpy(FullPath, *FileName, STRLEN);
119     if ((p = strrchr(FullPath, '/')) != NULL ||
120 	(p = strrchr(FullPath, '\\')) != NULL)
121 	p[1] = 0;
122     else if ((p = strrchr(FullPath, ':')) != NULL)
123 	p[1] = 0;
124     else
125 	FullPath[0] = 0;		  /* No directory or disk specified. */
126 
127     if ( strlen(FullPath) > STRLEN-1 ) GIF_EXIT("Filename too long.");
128     strncpy(FoutTmpName, FullPath, STRLEN);   /* First setup the Path */
129     /* then add a name for the tempfile */
130     if ( (strlen(FoutTmpName) + strlen(DEFAULT_TMP_NAME))  > STRLEN-1 ) GIF_EXIT("Filename too long.");
131     strcat(FoutTmpName, DEFAULT_TMP_NAME);
132 #ifdef _WIN32
133     char *tmpFN = _mktemp(FoutTmpName);
134     if (tmpFN)
135 	FD = open(tmpFN, O_CREAT | O_EXCL | O_WRONLY);
136     else
137 	FD = -1;
138 #else
139     FD = mkstemp(FoutTmpName); /* returns filedescriptor */
140 #endif
141     if (FD == -1 )
142     {
143 	GIF_EXIT("Failed to open output.");
144     }
145     Fout = fdopen(FD, "wb"); /* returns a stream with FD */
146     if (Fout == NULL )
147     {
148 	GIF_EXIT("Failed to open output.");
149     }
150 
151     while (1) {
152 	int c = getc(Fin);
153 
154 	if (feof(Fin))
155 	    break;
156 	if (putc(c, Fout) == EOF)
157 	    GIF_EXIT("Failed to write output.");
158     }
159 
160     fclose(Fin);
161     if (ftell(Fout) >= (long) MinFileSize) {
162 	fclose(Fout);
163 	unlink(*FileName);
164 	if (rename(FoutTmpName, *FileName) != 0) {
165 	    char DefaultName[STRLEN+1];
166 	    memset(DefaultName, '\0', sizeof(DefaultName));
167 	    if ( (strlen(FullPath) + strlen(DEFAULT_OUT_NAME)) > STRLEN-1 ) GIF_EXIT("Filename too long.");
168 	    strncpy(DefaultName, FullPath, STRLEN);
169 	    strcat(DefaultName, DEFAULT_OUT_NAME);
170 	    if (rename(FoutTmpName, DefaultName) == 0) {
171 		char s[STRLEN];
172 		snprintf(s, STRLEN, "Failed to rename out file - left as %s.",
173 			      DefaultName);
174 		GIF_MESSAGE(s);
175 	    }
176 	    else {
177 		unlink(FoutTmpName);
178 		GIF_MESSAGE("Failed to rename out file - deleted.");
179 	    }
180 	}
181     }
182     else {
183 	fclose(Fout);
184 	unlink(FoutTmpName);
185 	GIF_MESSAGE("File too small - not renamed.");
186     }
187 
188     return 0;
189 }
190 
191 /* end */
192