diff options
-rw-r--r-- | ch5/5-12_detab-spec.c | 75 | ||||
-rw-r--r-- | ch5/5-12_entab-spec.c | 82 |
2 files changed, 157 insertions, 0 deletions
diff --git a/ch5/5-12_detab-spec.c b/ch5/5-12_detab-spec.c new file mode 100644 index 0000000..ba22619 --- /dev/null +++ b/ch5/5-12_detab-spec.c @@ -0,0 +1,75 @@ +#include <stdio.h> +#include <ctype.h> + +/* The C Programming Language: 2nd Edition + * + * Exercise 5-12: Extend `entab` and `detab` to accept the shorthand + * `entab -m +n` to mean tab stops every n columns, starting at column m. + * Choose convenient (for the user) default behavior. + */ + +#define DEFAULTTAB 8 + +int main(int argc, char *argv[]) { + int column, c; + int tabstart = (-1); + int tabevery = (-1); + char arg[4]; + column = 0; + + if (argc > 1) { + int i = 1; + int j = 0; + while (--argc > 0) { + c = argv[i][j++]; + if (c == '-' || c == '+') { + while (isdigit(argv[i][j])) { + arg[j - 1] = argv[i][j]; + j++; + } + arg[3] = '\0'; + if (c == '-') { + tabstart = atoi(arg); + } else { + tabevery = atoi(arg); + } + j = 0; + } else { + printf("detab: unrecognized argument %s\n", *argv); + } + i++; + } + } + /* Clean up the mess if either argument hasn't been set to something sane */ + if (tabstart == -1) { + tabstart = 0; + } + if (tabevery == -1) { + tabevery = DEFAULTTAB; + } + + while ((c = getchar()) != EOF) { + column++; + + if (c == '\t') { + /* No point in processing our tabs until we're after the offset */ + if (column > tabstart) { + putchar(' '); + while ((column - tabstart) % tabevery != 0) { + putchar(' '); + column++; + } + } else { + putchar(' '); + } + } else { + /* reset the counts on a newline */ + if (c == '\n') { + column = 0; + } + putchar(c); + } + } + + return 0; +} diff --git a/ch5/5-12_entab-spec.c b/ch5/5-12_entab-spec.c new file mode 100644 index 0000000..c1f3f6b --- /dev/null +++ b/ch5/5-12_entab-spec.c @@ -0,0 +1,82 @@ +#include <stdio.h> +#include <stdlib.h> +#include <ctype.h> + +/* The C Programming Language: 2nd Edition + * + * Exercise 5-12: Extend `entab` and `detab` to accept the shorthand + * `entab -m +n` to mean tab stops every n columns, starting at column m. + * Choose convenient (for the user) default behavior. + */ + +#define DEFAULTTAB 8 + +int main(int argc, char *argv[]) { + int column, c, spaces; + int tabstart = (-1); + int tabevery = (-1); + char arg[4]; + spaces = column = 0; + + if (argc > 1) { + int i = 1; + int j = 0; + while (--argc > 0) { + c = argv[i][j++]; + if (c == '-' || c == '+') { + while (isdigit(argv[i][j])) { + arg[j - 1] = argv[i][j]; + j++; + } + arg[3] = '\0'; + if (c == '-') { + tabstart = atoi(arg); + } else { + tabevery = atoi(arg); + } + j = 0; + } else { + printf("entab: unrecognized argument %s\n", *argv); + } + i++; + } + } + /* Clean up the mess if either argument hasn't been set to something sane */ + if (tabstart == -1) { + tabstart = 0; + } + if (tabevery == -1) { + tabevery = DEFAULTTAB; + } + + while ((c = getchar()) != EOF) { + column++; + + if (c == ' ') { + /* No point in starting our tabs until we're after the offset */ + if (column > tabstart) { + spaces++; + if ((column - tabstart) % tabevery == 0) { + if (spaces > 1) { + putchar('\t'); + spaces = 0; + } + } + } + } else { + /* output all extra spaces first */ + while (spaces > 0) { + putchar(' '); + spaces--; + } + /* reset the counts and argument position on a newline */ + if (c == '\n') { + column = 0; + spaces = 0; + } + putchar(c); + } + } + + return 0; +} |