fe-print.c

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/*-------------------------------------------------------------------------
 *
 * fe-print.c
 *    functions for pretty-printing query results
 *
 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * These functions were formerly part of fe-exec.c, but they
 * didn't really belong there.
 *
 * IDENTIFICATION
 *    src/interfaces/libpq/fe-print.c
 *
 *-------------------------------------------------------------------------
 */
#include "postgres_fe.h"
 
#include <signal.h>
 
#ifdef WIN32
#include "win32.h"
#else
#include <unistd.h>
#include <sys/ioctl.h>
#endif
 
#ifdef HAVE_TERMIOS_H
#include <termios.h>
#else
#ifndef WIN32
#include <sys/termios.h>
#endif
#endif
 
#include "libpq-fe.h"
#include "libpq-int.h"
 
 
static bool do_field(const PQprintOpt *po, const PGresult *res,
                     const int i, const int j, const int fs_len,
                     char **fields,
                     const int nFields, const char **fieldNames,
                     unsigned char *fieldNotNum, int *fieldMax,
                     const int fieldMaxLen, FILE *fout);
static char *do_header(FILE *fout, const PQprintOpt *po, const int nFields,
                       int *fieldMax, const char **fieldNames, unsigned char *fieldNotNum,
                       const int fs_len, const PGresult *res);
static void output_row(FILE *fout, const PQprintOpt *po, const int nFields, char **fields,
                       unsigned char *fieldNotNum, int *fieldMax, char *border,
                       const int row_index);
static void fill(int length, int max, char filler, FILE *fp);
 
/*
 * PQprint()
 *
 * Format results of a query for printing.
 *
 * PQprintOpt is a typedef (structure) that contains
 * various flags and options. consult libpq-fe.h for
 * details
 *
 * This function should probably be removed sometime since psql
 * doesn't use it anymore. It is unclear to what extent this is used
 * by external clients, however.
 */
void
PQprint(FILE *fout, const PGresult *res, const PQprintOpt *po)
{
    int         nFields;
 
    nFields = PQnfields(res);
 
    if (nFields > 0)
    {                           /* only print rows with at least 1 field.  */
        int         i,
                    j;
        int         nTups;
        int        *fieldMax = NULL;    /* in case we don't use them */
        unsigned char *fieldNotNum = NULL;
        char       *border = NULL;
        char      **fields = NULL;
        const char **fieldNames = NULL;
        int         fieldMaxLen = 0;
        int         numFieldName;
        int         fs_len = strlen(po->fieldSep);
        int         total_line_length = 0;
        bool        usePipe = false;
        char       *pagerenv;
 
#if !defined(WIN32)
        sigset_t    osigset;
        bool        sigpipe_masked = false;
        bool        sigpipe_pending;
#endif
 
#ifdef TIOCGWINSZ
        struct winsize screen_size;
#else
        struct winsize
        {
            int         ws_row;
            int         ws_col;
        }           screen_size;
#endif
 
        nTups = PQntuples(res);
        fieldNames = (const char **) calloc(nFields, sizeof(char *));
        fieldNotNum = (unsigned char *) calloc(nFields, 1);
        fieldMax = (int *) calloc(nFields, sizeof(int));
        if (!fieldNames || !fieldNotNum || !fieldMax)
        {
            fprintf(stderr, libpq_gettext("out of memory\n"));
            goto exit;
        }
        for (numFieldName = 0;
             po->fieldName && po->fieldName[numFieldName];
             numFieldName++)
            ;
        for (j = 0; j < nFields; j++)
        {
            int         len;
            const char *s = (j < numFieldName && po->fieldName[j][0]) ?
                po->fieldName[j] : PQfname(res, j);
 
            fieldNames[j] = s;
            len = s ? strlen(s) : 0;
            fieldMax[j] = len;
            len += fs_len;
            if (len > fieldMaxLen)
                fieldMaxLen = len;
            total_line_length += len;
        }
 
        total_line_length += nFields * strlen(po->fieldSep) + 1;
 
        if (fout == NULL)
            fout = stdout;
        if (po->pager && fout == stdout && isatty(fileno(stdin)) &&
            isatty(fileno(stdout)))
        {
            /*
             * If we think there'll be more than one screen of output, try to
             * pipe to the pager program.
             */
#ifdef TIOCGWINSZ
            if (ioctl(fileno(stdout), TIOCGWINSZ, &screen_size) == -1 ||
                screen_size.ws_col == 0 ||
                screen_size.ws_row == 0)
            {
                screen_size.ws_row = 24;
                screen_size.ws_col = 80;
            }
#else
            screen_size.ws_row = 24;
            screen_size.ws_col = 80;
#endif
 
            /*
             * Since this function is no longer used by psql, we don't examine
             * PSQL_PAGER.  It's possible that the hypothetical external users
             * of the function would like that to happen, but in the name of
             * backwards compatibility, we'll stick to just examining PAGER.
             */
            pagerenv = getenv("PAGER");
            /* if PAGER is unset, empty or all-white-space, don't use pager */
            if (pagerenv != NULL &&
                strspn(pagerenv, " \t\r\n") != strlen(pagerenv) &&
                !po->html3 &&
                ((po->expanded &&
                  nTups * (nFields + 1) >= screen_size.ws_row) ||
                 (!po->expanded &&
                  nTups * (total_line_length / screen_size.ws_col + 1) *
                  (1 + (po->standard != 0)) >= screen_size.ws_row -
                  (po->header != 0) *
                  (total_line_length / screen_size.ws_col + 1) * 2
                  - (po->header != 0) * 2   /* row count and newline */
                  )))
            {
                fflush(NULL);
                fout = popen(pagerenv, "w");
                if (fout)
                {
                    usePipe = true;
#ifndef WIN32
                    if (pq_block_sigpipe(&osigset, &sigpipe_pending) == 0)
                        sigpipe_masked = true;
#endif                          /* WIN32 */
                }
                else
                    fout = stdout;
            }
        }
 
        if (!po->expanded && (po->align || po->html3))
        {
            fields = (char **) calloc((size_t) nTups + 1,
                                      nFields * sizeof(char *));
            if (!fields)
            {
                fprintf(stderr, libpq_gettext("out of memory\n"));
                goto exit;
            }
        }
        else if (po->header && !po->html3)
        {
            if (po->expanded)
            {
                if (po->align)
                    fprintf(fout, libpq_gettext("%-*s%s Value\n"),
                            fieldMaxLen - fs_len, libpq_gettext("Field"), po->fieldSep);
                else
                    fprintf(fout, libpq_gettext("%s%sValue\n"), libpq_gettext("Field"), po->fieldSep);
            }
            else
            {
                int         len = 0;
 
                for (j = 0; j < nFields; j++)
                {
                    const char *s = fieldNames[j];
 
                    fputs(s, fout);
                    len += strlen(s) + fs_len;
                    if ((j + 1) < nFields)
                        fputs(po->fieldSep, fout);
                }
                fputc('\n', fout);
                for (len -= fs_len; len--; fputc('-', fout));
                fputc('\n', fout);
            }
        }
        if (po->expanded && po->html3)
        {
            if (po->caption)
                fprintf(fout, "<center><h2>%s</h2></center>\n", po->caption);
            else
                fprintf(fout,
                        "<center><h2>"
                        "Query retrieved %d rows * %d fields"
                        "</h2></center>\n",
                        nTups, nFields);
        }
        for (i = 0; i < nTups; i++)
        {
            if (po->expanded)
            {
                if (po->html3)
                    fprintf(fout,
                            "<table %s><caption align=\"top\">%d</caption>\n",
                            po->tableOpt ? po->tableOpt : "", i);
                else
                    fprintf(fout, libpq_gettext("-- RECORD %d --\n"), i);
            }
            for (j = 0; j < nFields; j++)
            {
                if (!do_field(po, res, i, j, fs_len, fields, nFields,
                              fieldNames, fieldNotNum,
                              fieldMax, fieldMaxLen, fout))
                    goto exit;
            }
            if (po->html3 && po->expanded)
                fputs("</table>\n", fout);
        }
        if (!po->expanded && (po->align || po->html3))
        {
            if (po->html3)
            {
                if (po->header)
                {
                    if (po->caption)
                        fprintf(fout,
                                "<table %s><caption align=\"top\">%s</caption>\n",
                                po->tableOpt ? po->tableOpt : "",
                                po->caption);
                    else
                        fprintf(fout,
                                "<table %s><caption align=\"top\">"
                                "Retrieved %d rows * %d fields"
                                "</caption>\n",
                                po->tableOpt ? po->tableOpt : "", nTups, nFields);
                }
                else
                    fprintf(fout, "<table %s>", po->tableOpt ? po->tableOpt : "");
            }
            if (po->header)
                border = do_header(fout, po, nFields, fieldMax, fieldNames,
                                   fieldNotNum, fs_len, res);
            for (i = 0; i < nTups; i++)
                output_row(fout, po, nFields, fields,
                           fieldNotNum, fieldMax, border, i);
        }
        if (po->header && !po->html3)
            fprintf(fout, "(%d row%s)\n\n", PQntuples(res),
                    (PQntuples(res) == 1) ? "" : "s");
        if (po->html3 && !po->expanded)
            fputs("</table>\n", fout);
 
exit:
        free(fieldMax);
        free(fieldNotNum);
        free(border);
        if (fields)
        {
            /* if calloc succeeded, this shouldn't overflow size_t */
            size_t      numfields = ((size_t) nTups + 1) * (size_t) nFields;
 
            while (numfields-- > 0)
                free(fields[numfields]);
            free(fields);
        }
        free(fieldNames);
        if (usePipe)
        {
#ifdef WIN32
            _pclose(fout);
#else
            pclose(fout);
 
            /* we can't easily verify if EPIPE occurred, so say it did */
            if (sigpipe_masked)
                pq_reset_sigpipe(&osigset, sigpipe_pending, true);
#endif                          /* WIN32 */
        }
    }
}
 
 
static bool
do_field(const PQprintOpt *po, const PGresult *res,
         const int i, const int j, const int fs_len,
         char **fields,
         const int nFields, char const **fieldNames,
         unsigned char *fieldNotNum, int *fieldMax,
         const int fieldMaxLen, FILE *fout)
{
    const char *pval,
               *p;
    int         plen;
    bool        skipit;
 
    plen = PQgetlength(res, i, j);
    pval = PQgetvalue(res, i, j);
 
    if (plen < 1 || !pval || !*pval)
    {
        if (po->align || po->expanded)
            skipit = true;
        else
        {
            skipit = false;
            goto efield;
        }
    }
    else
        skipit = false;
 
    if (!skipit)
    {
        if (po->align && !fieldNotNum[j])
        {
            /* Detect whether field contains non-numeric data */
            char        ch = '0';
 
            for (p = pval; *p; p += PQmblenBounded(p, res->client_encoding))
            {
                ch = *p;
                if (!((ch >= '0' && ch <= '9') ||
                      ch == '.' ||
                      ch == 'E' ||
                      ch == 'e' ||
                      ch == ' ' ||
                      ch == '-'))
                {
                    fieldNotNum[j] = 1;
                    break;
                }
            }
 
            /*
             * Above loop will believe E in first column is numeric; also, we
             * insist on a digit in the last column for a numeric. This test
             * is still not bulletproof but it handles most cases.
             */
            if (*pval == 'E' || *pval == 'e' ||
                !(ch >= '0' && ch <= '9'))
                fieldNotNum[j] = 1;
        }
 
        if (!po->expanded && (po->align || po->html3))
        {
            if (plen > fieldMax[j])
                fieldMax[j] = plen;
            if (!(fields[i * nFields + j] = (char *) malloc(plen + 1)))
            {
                fprintf(stderr, libpq_gettext("out of memory\n"));
                return false;
            }
            strcpy(fields[i * nFields + j], pval);
        }
        else
        {
            if (po->expanded)
            {
                if (po->html3)
                    fprintf(fout,
                            "<tr><td align=\"left\"><b>%s</b></td>"
                            "<td align=\"%s\">%s</td></tr>\n",
                            fieldNames[j],
                            fieldNotNum[j] ? "left" : "right",
                            pval);
                else
                {
                    if (po->align)
                        fprintf(fout,
                                "%-*s%s %s\n",
                                fieldMaxLen - fs_len, fieldNames[j],
                                po->fieldSep,
                                pval);
                    else
                        fprintf(fout,
                                "%s%s%s\n",
                                fieldNames[j], po->fieldSep, pval);
                }
            }
            else
            {
                if (!po->html3)
                {
                    fputs(pval, fout);
            efield:
                    if ((j + 1) < nFields)
                        fputs(po->fieldSep, fout);
                    else
                        fputc('\n', fout);
                }
            }
        }
    }
    return true;
}
 
 
static char *
do_header(FILE *fout, const PQprintOpt *po, const int nFields, int *fieldMax,
          const char **fieldNames, unsigned char *fieldNotNum,
          const int fs_len, const PGresult *res)
{
    int         j;              /* for loop index */
    char       *border = NULL;
 
    if (po->html3)
        fputs("<tr>", fout);
    else
    {
        int         tot = 0;
        int         n = 0;
        char       *p = NULL;
 
        for (; n < nFields; n++)
            tot += fieldMax[n] + fs_len + (po->standard ? 2 : 0);
        if (po->standard)
            tot += fs_len * 2 + 2;
        border = malloc(tot + 1);
        if (!border)
        {
            fprintf(stderr, libpq_gettext("out of memory\n"));
            return NULL;
        }
        p = border;
        if (po->standard)
        {
            char       *fs = po->fieldSep;
 
            while (*fs++)
                *p++ = '+';
        }
        for (j = 0; j < nFields; j++)
        {
            int         len;
 
            for (len = fieldMax[j] + (po->standard ? 2 : 0); len--; *p++ = '-');
            if (po->standard || (j + 1) < nFields)
            {
                char       *fs = po->fieldSep;
 
                while (*fs++)
                    *p++ = '+';
            }
        }
        *p = '\0';
        if (po->standard)
            fprintf(fout, "%s\n", border);
    }
    if (po->standard)
        fputs(po->fieldSep, fout);
    for (j = 0; j < nFields; j++)
    {
        const char *s = PQfname(res, j);
 
        if (po->html3)
        {
            fprintf(fout, "<th align=\"%s\">%s</th>",
                    fieldNotNum[j] ? "left" : "right", fieldNames[j]);
        }
        else
        {
            int         n = strlen(s);
 
            if (n > fieldMax[j])
                fieldMax[j] = n;
            if (po->standard)
                fprintf(fout,
                        fieldNotNum[j] ? " %-*s " : " %*s ",
                        fieldMax[j], s);
            else
                fprintf(fout, fieldNotNum[j] ? "%-*s" : "%*s", fieldMax[j], s);
            if (po->standard || (j + 1) < nFields)
                fputs(po->fieldSep, fout);
        }
    }
    if (po->html3)
        fputs("</tr>\n", fout);
    else
        fprintf(fout, "\n%s\n", border);
    return border;
}
 
 
static void
output_row(FILE *fout, const PQprintOpt *po, const int nFields, char **fields,
           unsigned char *fieldNotNum, int *fieldMax, char *border,
           const int row_index)
{
    int         field_index;    /* for loop index */
 
    if (po->html3)
        fputs("<tr>", fout);
    else if (po->standard)
        fputs(po->fieldSep, fout);
    for (field_index = 0; field_index < nFields; field_index++)
    {
        char       *p = fields[row_index * nFields + field_index];
 
        if (po->html3)
            fprintf(fout, "<td align=\"%s\">%s</td>",
                    fieldNotNum[field_index] ? "left" : "right", p ? p : "");
        else
        {
            fprintf(fout,
                    fieldNotNum[field_index] ?
                    (po->standard ? " %-*s " : "%-*s") :
                    (po->standard ? " %*s " : "%*s"),
                    fieldMax[field_index],
                    p ? p : "");
            if (po->standard || field_index + 1 < nFields)
                fputs(po->fieldSep, fout);
        }
    }
    if (po->html3)
        fputs("</tr>", fout);
    else if (po->standard)
        fprintf(fout, "\n%s", border);
    fputc('\n', fout);
}
 
 
 
/*
 * really old printing routines
 */
 
void
PQdisplayTuples(const PGresult *res,
                FILE *fp,       /* where to send the output */
                int fillAlign,  /* pad the fields with spaces */
                const char *fieldSep,   /* field separator */
                int printHeader,    /* display headers? */
                int quiet
)
{
#define DEFAULT_FIELD_SEP " "
 
    int         i,
                j;
    int         nFields;
    int         nTuples;
    int        *fLength = NULL;
 
    if (fieldSep == NULL)
        fieldSep = DEFAULT_FIELD_SEP;
 
    /* Get some useful info about the results */
    nFields = PQnfields(res);
    nTuples = PQntuples(res);
 
    if (fp == NULL)
        fp = stdout;
 
    /* Figure the field lengths to align to */
    /* will be somewhat time consuming for very large results */
    if (fillAlign)
    {
        fLength = (int *) malloc(nFields * sizeof(int));
        if (!fLength)
        {
            fprintf(stderr, libpq_gettext("out of memory\n"));
            return;
        }
 
        for (j = 0; j < nFields; j++)
        {
            fLength[j] = strlen(PQfname(res, j));
            for (i = 0; i < nTuples; i++)
            {
                int         flen = PQgetlength(res, i, j);
 
                if (flen > fLength[j])
                    fLength[j] = flen;
            }
        }
    }
 
    if (printHeader)
    {
        /* first, print out the attribute names */
        for (i = 0; i < nFields; i++)
        {
            fputs(PQfname(res, i), fp);
            if (fillAlign)
                fill(strlen(PQfname(res, i)), fLength[i], ' ', fp);
            fputs(fieldSep, fp);
        }
        fprintf(fp, "\n");
 
        /* Underline the attribute names */
        for (i = 0; i < nFields; i++)
        {
            if (fillAlign)
                fill(0, fLength[i], '-', fp);
            fputs(fieldSep, fp);
        }
        fprintf(fp, "\n");
    }
 
    /* next, print out the instances */
    for (i = 0; i < nTuples; i++)
    {
        for (j = 0; j < nFields; j++)
        {
            fprintf(fp, "%s", PQgetvalue(res, i, j));
            if (fillAlign)
                fill(strlen(PQgetvalue(res, i, j)), fLength[j], ' ', fp);
            fputs(fieldSep, fp);
        }
        fprintf(fp, "\n");
    }
 
    if (!quiet)
        fprintf(fp, "\nQuery returned %d row%s.\n", PQntuples(res),
                (PQntuples(res) == 1) ? "" : "s");
 
    fflush(fp);
 
    free(fLength);
}
 
 
 
void
PQprintTuples(const PGresult *res,
              FILE *fout,       /* output stream */
              int PrintAttNames,    /* print attribute names or not */
              int TerseOutput,  /* delimiter bars or not? */
              int colWidth      /* width of column, if 0, use variable width */
)
{
    int         nFields;
    int         nTups;
    int         i,
                j;
    char        formatString[80];
    char       *tborder = NULL;
 
    nFields = PQnfields(res);
    nTups = PQntuples(res);
 
    if (colWidth > 0)
        sprintf(formatString, "%%s %%-%ds", colWidth);
    else
        sprintf(formatString, "%%s %%s");
 
    if (nFields > 0)
    {                           /* only print rows with at least 1 field.  */
 
        if (!TerseOutput)
        {
            int         width;
 
            width = nFields * 14;
            tborder = (char *) malloc(width + 1);
            if (!tborder)
            {
                fprintf(stderr, libpq_gettext("out of memory\n"));
                return;
            }
            for (i = 0; i < width; i++)
                tborder[i] = '-';
            tborder[width] = '\0';
            fprintf(fout, "%s\n", tborder);
        }
 
        for (i = 0; i < nFields; i++)
        {
            if (PrintAttNames)
            {
                fprintf(fout, formatString,
                        TerseOutput ? "" : "|",
                        PQfname(res, i));
            }
        }
 
        if (PrintAttNames)
        {
            if (TerseOutput)
                fprintf(fout, "\n");
            else
                fprintf(fout, "|\n%s\n", tborder);
        }
 
        for (i = 0; i < nTups; i++)
        {
            for (j = 0; j < nFields; j++)
            {
                const char *pval = PQgetvalue(res, i, j);
 
                fprintf(fout, formatString,
                        TerseOutput ? "" : "|",
                        pval ? pval : "");
            }
            if (TerseOutput)
                fprintf(fout, "\n");
            else
                fprintf(fout, "|\n%s\n", tborder);
        }
    }
 
    free(tborder);
}
 
 
/* simply send out max-length number of filler characters to fp */
 
static void
fill(int length, int max, char filler, FILE *fp)
{
    int         count;
 
    count = max - length;
    while (count-- >= 0)
        putc(filler, fp);
}