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96cd660ad0
C23 does not allow K&R style function definitions. Use protyped definitions. However, don't bother with (void) in function definitions since C23 prefers (); so prefer () to (void) as this will work with older compilers anyway.
55 lines
1.4 KiB
C
55 lines
1.4 KiB
C
#include <config.h>
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#include <stdio.h>
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#include <stdlib.h>
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/* Trivial example of reading a gzip'ed file or gzip'ed standard input
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* using stdio functions fread(), getc(), etc... fseek() is not supported.
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* Modify according to your needs. You can easily construct the symmetric
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* zwrite program.
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*
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* Usage: zread [file[.gz]]
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* This programs assumes that gzip is somewhere in your path.
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*/
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int
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main (int argc, char **argv)
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{
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FILE *infile;
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char cmd[256];
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char buf[BUFSIZ];
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int n;
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if (argc < 1 || argc > 2) {
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fprintf(stderr, "usage: %s [file[.gz]]\n", argv[0]);
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exit(EXIT_FAILURE);
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}
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strcpy(cmd, "gzip -dc "); /* use "gzip -c" for zwrite */
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if (argc == 2) {
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strncat(cmd, argv[1], sizeof(cmd)-strlen(cmd));
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}
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infile = popen(cmd, "r"); /* use "w" for zwrite */
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if (infile == NULL) {
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fprintf(stderr, "%s: popen('%s', 'r') failed\n", argv[0], cmd);
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exit(EXIT_FAILURE);
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}
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/* Read one byte using getc: */
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n = getc(infile);
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if (n == EOF) {
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pclose(infile);
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exit(EXIT_SUCCESS);
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}
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putchar(n);
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/* Read the rest using fread: */
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for (;;) {
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n = fread(buf, 1, BUFSIZ, infile);
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if (n <= 0) break;
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fwrite(buf, 1, n, stdout);
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}
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if (pclose(infile) != 0) {
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fprintf(stderr, "%s: pclose failed\n", argv[0]);
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exit(EXIT_FAILURE);
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}
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exit(EXIT_SUCCESS);
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return 0; /* just to make compiler happy */
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}
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