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/*
bash-inflate(){ (printf "\x1f\x8b\x08\x00\x00\x00\x00\x00\x00"&&cat -)|gzip -dc; }
*/
#include "commonbase.h"
/* system */
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
/* libs */
#include "zlib.h"
typedef unsigned char uchar; /* TODO cleanup */
typedef struct MyInflate MyInflate;
struct MyInflate {
int tryParseHeaders;
};
static void printHelp( void ){
printf("\n %s%s", strrchr(__FILE__,'/')+1, " @ " STR_QUOT(PROJECT_VERSION) "\n"
"\n"
"inflates stdin to stdout\n"
"\n"
"Options:\n"
"\n"
" --raw\n"
" By default, we'll try to decode leading headers. Using this\n"
" option, no header parsing is done and the input is expected to\n"
" be a pure deflate stream.\n"
"\n"
"\n");
}
static int parseArgs( int argc, char**argv, MyInflate*myInflate ){
myInflate->tryParseHeaders = !0; /* enabled by default */
for( int i = 1 ; i < argc ; ++i ){
char *arg = argv[i];
if( !strcmp(arg,"--help") ){
printHelp(); return -1;
}else if( !strcmp(arg,"--raw") ){
myInflate->tryParseHeaders = 0;
}else{
fprintf(stderr, "Unknown arg: %s\n", arg);
return -1;
}
}
return 0;
}
static int doInflate( MyInflate*myInflate ){
#define MAX(a, b) ((a) > (b) ? (a) : (b))
int err;
z_stream strm;
uchar innBuf[65536];
const int innBuf_cap = sizeof innBuf;
int innBuf_len = 0, innBuf_off = 0;
uchar outBuf[65536];
const int outBuf_cap = sizeof outBuf;
int outBuf_len = 0;
int inputIsEOF = 0;
int outputIsEOF = 0;
int noProgressSince = 0;
/* only counts while reading through possible file headers. Later, the
* counter will not be updated anymore, to prevent overflows */
int headerIsPassed = 0;
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.next_in = innBuf;
strm.avail_in = innBuf_len;
// Pass special 2nd arg. See "https://codeandlife.com/2014/01/01/unzip-library-for-c/"
err = inflateInit2(&strm, -MAX_WBITS);
if( err != Z_OK ){
fprintf(stderr, "Error: inflateInit() ret=%d: %s\n", err, strerror(errno));
return -1;
}
for(; !inputIsEOF || !outputIsEOF ;){
/* input */ {
int space = innBuf_cap - innBuf_len;
/* look if we can shift */
if( space <= 0 && innBuf_off > 0 ){
int wr = 0, rd = innBuf_off;
for(;;){
err = rd - wr; /* chunk length to copy */
if( rd + err > innBuf_cap) err = innBuf_cap - rd;
if( err <= 0 ) break;
memcpy(innBuf + wr, innBuf + rd, err);
rd += err;
wr += err;
}
innBuf_len -= innBuf_off;
innBuf_off = 0;
space = innBuf_cap - innBuf_len;
}
if( space > 0 && !inputIsEOF ){
err = fread(innBuf + innBuf_len, 1, space, stdin);
if(unlikely( err <= 0 )){
if( feof(stdin) ){
inputIsEOF = !0;
}else{
fprintf(stderr, "Error: fread(): %s\n", strerror(errno));
return -1;
}
}
assert(err <= space);
innBuf_len += err;
}
}
if(unlikely( !headerIsPassed )){
#define avail (innBuf_len - innBuf_off)
/* Ensure we have at least two bytes for zlib header detection */
if( avail < 2 && !inputIsEOF ){
#ifndef NDEBUG
fprintf(stderr, "[DEBUG] Not enough data for header detection. have %d\n", avail);
#endif
continue;
}
headerIsPassed = !0;
if( myInflate->tryParseHeaders ){
int b0 = innBuf[0], b1 = innBuf[1];
if( b0 == 0x78 && (b1 == 0x01 || b1 == 0x5E || b1 == 0x9C || b1 == 0xDA) ){
innBuf_off += 2;
}
}
#undef avail
}
/* process */ {
strm.next_in = innBuf + innBuf_off;
strm.avail_in = MAX(0, innBuf_len - innBuf_off);
strm.next_out = outBuf;
strm.avail_out = outBuf_cap;
// TODO remove assert(strm.avail_in >= 0 || inputIsEOF);
assert(strm.avail_out > 0);
int flush = inputIsEOF ? Z_FINISH : Z_NO_FLUSH;
errno = 0;
err = inflate(&strm, flush);
if(unlikely( err != Z_OK )){
if( err == Z_STREAM_END ){
outputIsEOF = !0;
}else if( err == Z_BUF_ERROR ){
/* Could not make any progress. Have to call again with updated buffers */
noProgressSince += 1;
if( noProgressSince > 42 ){
fprintf(stderr, "Warn: inflate() -> Z_BUF_ERROR: %s (maybe EOF came too early?)\n",
(strm.msg == NULL) ? "Could not make any progress" : strm.msg);
return -1;
}
}else if( strm.msg != NULL || errno ){
fprintf(stderr, "Error: inflate(): %s\n", (strm.msg != NULL) ? strm.msg :
strerror(errno));
return -1;
}else{
fprintf(stderr, "Error: inflate(): -> %d\n", err);
return -1;
}
}else{
noProgressSince = 0; /* reset as we just made progress */
}
innBuf_off += strm.next_in - innBuf;
outBuf_len = strm.next_out - outBuf;
if( innBuf_off > innBuf_len ){ innBuf_off = innBuf_len; }
}
/* output */ {
err = fwrite(outBuf, 1, outBuf_len, stdout);
if(unlikely( err != outBuf_len )){
fprintf(stderr, "Errro: fwrite(): %s\n", strerror(errno));
return -1;
}
outBuf_len = 0;
}
}
err = inflateEnd(&strm);
if( err != Z_OK ){
fprintf(stderr, "Warn: inflateEnd() ret=%d: %s\n", err, strm.msg);
}
return 0;
#undef MAX
}
int inflate_main( int argc, char**argv ){
int err;
MyInflate myInflate;
#define myInflate (&myInflate)
err = parseArgs(argc, argv, myInflate);
if( err < 0 ){ return err; }
fixBrokenStdio();
err = doInflate(myInflate);
if( err < 0 ){ return err; }
return 0;
#undef myInflate
}
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