more: use off_t and cc_t to clarify what variables attempt to represent

As a minor robustness improvement use ftello() to find out file position
rather than add and substract from old value.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/text-utils/more.c b/text-utils/more.c
index 0b3e838288dde2d6ea5652b19d832b9491ec2de5..a2542de86bafd0bbcbf88b39ba49e6f094b6b821 100644 (file)
--- a/text-utils/more.c
+++ b/text-utils/more.c
@@ -126,8 +126,8 @@ struct more_control {
        struct termios output_tty;      /* output terminal */
        struct termios original_tty;    /* original terminal settings */
        FILE *current_file;             /* currently open input file */
-       long file_position;             /* file position */
-       long file_size;                 /* file size */
+       off_t file_position;            /* file position */
+       off_t file_size;                /* file size */
        int argv_position;              /* argv[] position */
        int lines_per_screen;           /* screen size in lines */
        int d_scroll_len;               /* number of lines scrolled by 'd' */
@@ -155,11 +155,11 @@ struct more_control {
        int num_columns;                /* number of columns */
        char *previous_search;          /* previous search() buf[] item */
        struct {
-               long row_num;           /* row number */
+               off_t row_num;          /* row file position */
                long line_num;          /* line number */
        } context,
          screen_start;
-       int last_key_command;           /* previous more key command */
+       cc_t last_key_command;          /* previous more key command */
        int last_key_arg;               /* previous key command argument */
        int last_colon_command;         /* is a colon-prefixed key command */
        char *shell_line;               /* line to execute in subshell */
@@ -286,22 +286,24 @@ static void arg_parser(struct more_control *ctl, char *s)
        }
 }
 
-static void more_fseek(struct more_control *ctl, long pos)
+static void more_fseek(struct more_control *ctl, off_t pos)
 {
        ctl->file_position = pos;
-       fseek(ctl->current_file, pos, 0);
+       fseeko(ctl->current_file, pos, SEEK_SET);
 }
 
 static int more_getc(struct more_control *ctl)
 {
-       ctl->file_position++;
-       return getc(ctl->current_file);
+       int ret = getc(ctl->current_file);
+       ctl->file_position = ftello(ctl->current_file);
+       return ret;
 }
 
 static int more_ungetc(struct more_control *ctl, int c)
 {
-       ctl->file_position--;
-       return ungetc(c, ctl->current_file);
+       int ret = ungetc(c, ctl->current_file);
+       ctl->file_position = ftello(ctl->current_file);
+       return ret;
 }
 
 static void print_separator(const int c, int n)
@@ -378,7 +380,7 @@ static void checkf(struct more_control *ctl, char *fs)
        ctl->clear_first = (c == '\f');
        more_ungetc(ctl, c);
        if ((ctl->file_size = st.st_size) == 0)
-               ctl->file_size = LONG_MAX;
+               ctl->file_size = ~((off_t)0);
 }
 
 static void prepare_line_buffer(struct more_control *ctl)
@@ -414,7 +416,7 @@ static int get_line(struct more_control *ctl, int *length)
        size_t mbc_pos = 0;             /* Position of the MBC. */
        int use_mbc_buffer_flag = 0;    /* If 1, mbc has data. */
        int break_flag = 0;             /* If 1, exit while(). */
-       long file_position_bak = ctl->file_position;
+       off_t file_position_bak = ctl->file_position;
 
        memset(&state, '\0', sizeof(mbstate_t));
 #endif
@@ -763,9 +765,9 @@ static void __attribute__((__noreturn__)) more_exit(struct more_control *ctl)
        _exit(EXIT_SUCCESS);
 }
 
-static int read_user_input(struct more_control *ctl)
+static cc_t read_user_input(struct more_control *ctl)
 {
-       unsigned char c;
+       cc_t c;
 
        errno = 0;
        if (read(STDERR_FILENO, &c, 1) <= 0) {
@@ -779,10 +781,10 @@ static int read_user_input(struct more_control *ctl)
 
 /* Read a decimal number from the terminal.  Set cmd to the non-digit
  * which terminates the number. */
-static int read_number(struct more_control *ctl, char *cmd)
+static int read_number(struct more_control *ctl, cc_t *cmd)
 {
        int i;
-       char ch;
+       cc_t ch;
 
        i = 0;
        ch = ctl->output_tty.c_cc[VKILL];
@@ -790,7 +792,7 @@ static int read_number(struct more_control *ctl, char *cmd)
                ch = read_user_input(ctl);
                if (isdigit(ch))
                        i = i * 10 + ch - '0';
-               else if ((cc_t) ch == ctl->output_tty.c_cc[VKILL])
+               else if (ch == ctl->output_tty.c_cc[VKILL])
                        i = 0;
                else {
                        *cmd = ch;
@@ -865,7 +867,7 @@ static void erase_one_column(struct more_control *ctl)
 static void ttyin(struct more_control *ctl, char buf[], int nmax, char pchar)
 {
        char *sp;
-       int c;
+       cc_t c;
        int slash = 0;
        int maxlen;
 
@@ -877,7 +879,7 @@ static void ttyin(struct more_control *ctl, char buf[], int nmax, char pchar)
                c = read_user_input(ctl);
                if (c == '\\') {
                        slash++;
-               } else if (((cc_t) c == ctl->output_tty.c_cc[VERASE]) && !slash) {
+               } else if (c == ctl->output_tty.c_cc[VERASE] && !slash) {
                        if (sp > buf) {
 #ifdef HAVE_WIDECHAR
                                if (MB_CUR_MAX > 1) {
@@ -941,7 +943,7 @@ static void ttyin(struct more_control *ctl, char buf[], int nmax, char pchar)
                                if (!ctl->erase_line)
                                        ctl->prompt_len = maxlen;
                        }
-               } else if (((cc_t) c == ctl->output_tty.c_cc[VKILL]) && !slash) {
+               } else if (c == ctl->output_tty.c_cc[VKILL] && !slash) {
                        if (ctl->hard_tty) {
                                show(ctl, c);
                                putchar('\n');
@@ -960,8 +962,8 @@ static void ttyin(struct more_control *ctl, char buf[], int nmax, char pchar)
                        fflush(stdout);
                        continue;
                }
-               if (slash && ((cc_t) c == ctl->output_tty.c_cc[VKILL]
-                             || (cc_t) c == ctl->output_tty.c_cc[VERASE])) {
+               if (slash && (c == ctl->output_tty.c_cc[VKILL] ||
+                             c == ctl->output_tty.c_cc[VERASE])) {
                        erase_one_column(ctl);
                        --sp;
                }
@@ -1263,7 +1265,7 @@ static void read_line(struct more_control *ctl)
 
        p = ctl->line_buf;
        while ((c = more_getc(ctl)) != '\n' && c != EOF
-              && (size_t)(p - ctl->line_buf) < ctl->line_sz - 1)
+              && (ptrdiff_t)p != (ptrdiff_t)(ctl->line_buf + ctl->line_sz - 1))
                *p++ = c;
        if (c == '\n')
                ctl->current_line++;
@@ -1317,10 +1319,10 @@ static int more_poll(struct more_control *ctl, int timeout)
  * the file */
 static void search(struct more_control *ctl, char buf[], int n)
 {
-       long startline = ctl->file_position;
-       long line1 = startline;
-       long line2 = startline;
-       long line3;
+       off_t startline = ctl->file_position;
+       off_t line1 = startline;
+       off_t line2 = startline;
+       off_t line3;
        int lncount;
        int saveln, rc;
        regex_t re;
@@ -1498,7 +1500,7 @@ static int skip_backwards(struct more_control *ctl, int nlines)
                initline--;
        if (initline < 0)
                initline = 0;
-       more_fseek(ctl, 0L);
+       more_fseek(ctl, 0);
        ctl->current_line = 0;  /* skip_lines() will make current_line correct */
        skip_lines(ctl, initline);
        if (!ctl->no_scroll)
@@ -1508,7 +1510,7 @@ static int skip_backwards(struct more_control *ctl, int nlines)
        return retval;
 }
 
-static int skip_forwards(struct more_control *ctl, int nlines, char comchar)
+static int skip_forwards(struct more_control *ctl, int nlines, cc_t comchar)
 {
        int c;
 
@@ -1546,9 +1548,10 @@ static int more_key_command(struct more_control *ctl, char *filename)
 {
        int nlines;
        int retval = 0;
-       char colonch;
+       cc_t colonch;
        int done = 0;
-       char comchar, cmdbuf[INIT_BUF];
+       cc_t comchar;
+       char cmdbuf[INIT_BUF];
        if (!ctl->report_errors)
                output_prompt(ctl, filename);
        else
@@ -1568,7 +1571,7 @@ static int more_key_command(struct more_control *ctl, char *filename)
                }
                ctl->last_key_command = comchar;
                ctl->last_key_arg = nlines;
-               if ((cc_t) comchar == ctl->output_tty.c_cc[VERASE]) {
+               if (comchar == ctl->output_tty.c_cc[VERASE]) {
                        kill_line(ctl);
                        output_prompt(ctl, filename);
                        continue;
@@ -1818,7 +1821,7 @@ static void display_file(struct more_control *ctl, char *initbuf, int left)
                    more_key_command(ctl, ctl->file_names[ctl->argv_position]);
        if (left != 0) {
                if ((ctl->no_scroll || ctl->clear_first)
-                   && (ctl->file_size != LONG_MAX)) {
+                   && ctl->file_size != ~((off_t)0)) {
                        if (ctl->clear_line_ends)
                                putp(ctl->go_home);
                        else
@@ -1849,7 +1852,7 @@ static void display_file(struct more_control *ctl, char *initbuf, int left)
        fflush(stdout);
        fclose(ctl->current_file);
        ctl->current_file = NULL;
-       ctl->screen_start.line_num = ctl->screen_start.row_num = 0L;
+       ctl->screen_start.line_num = ctl->screen_start.row_num = 0;
        ctl->context.line_num = ctl->context.row_num = 0L;
 }