129 lines
2.0 KiB
C
129 lines
2.0 KiB
C
/* cmp.c */
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#include <unistd.h>
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#include <stdio.h>
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#include <string.h>
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/* types */
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typedef enum _OutputType {
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OT_NONE,
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OT_LONG,
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OT_DEFAULT
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} OutputType;
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/* cmp */
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static int _cmp_files(OutputType ot, char * file1, char * file2,
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FILE * fp1, FILE * fp2);
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static int _cmp(OutputType ot, char * file1, char * file2)
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{
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FILE * fp1;
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FILE * fp2;
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if(strcmp("-", file1) == 0)
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fp1 = stdin;
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else if((fp1 = fopen(file1, "r")) == NULL)
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{
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perror("fopen");
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return 2;
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}
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if(strcmp("-", file2) == 0)
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fp2 = stdin;
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else if((fp2 = fopen(file2, "r")) == NULL)
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{
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perror("fopen");
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if(fp1 != stdin)
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fclose(fp1);
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return 2;
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}
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return _cmp_files(ot, file1, file2, fp1, fp2);
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}
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static int _cmp_files(OutputType ot, char * file1, char * file2,
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FILE * fp1, FILE * fp2)
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{
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int c1;
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int c2;
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unsigned int byte = 1;
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unsigned int line = 1;
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int res = 0;
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while(1)
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{
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c1 = fgetc(fp1);
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c2 = fgetc(fp2);
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if(c1 == EOF && c2 == EOF)
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break;
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if(c1 == EOF || c2 == EOF)
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{
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if(ot != OT_NONE)
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fprintf(stderr, "%s%s\n",
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"cmp: EOF on ",
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c1 == EOF ? file1 : file2);
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res = 1;
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break;
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}
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if(c1 != c2)
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{
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res = 1;
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if(ot == OT_DEFAULT)
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{
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printf("%s %s differ: char %u, line %u\n",
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file1, file2, byte, line);
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break;
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}
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else if(ot == OT_LONG)
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printf("%d %o %o\n", byte, c1, c2);
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else
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break;
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}
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if(c1 == '\n')
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line++;
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byte++;
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}
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if(fp1 != stdin)
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fclose(fp1);
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if(fp2 != stdin)
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fclose(fp2);
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return res;
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}
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/* usage */
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static int _usage(void)
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{
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fprintf(stderr, "%s", "Usage: cmp [-l|-s] file1 file2\n\
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-l write the byte number and the differing byte for each difference\n\
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-s write nothing for differing bytes\n");
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return 2;
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}
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/* main */
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int main(int argc, char * argv[])
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{
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OutputType ot = OT_DEFAULT;
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int o;
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while((o = getopt(argc, argv, "ls")) != -1)
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{
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switch(o)
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{
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case 'l':
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ot = OT_LONG;
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break;
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case 's':
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ot = OT_NONE;
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break;
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case '?':
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return _usage();
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}
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}
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if(argc - optind != 2)
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return _usage();
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return _cmp(ot, argv[optind], argv[optind+1]);
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}
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