Você poderia fazer isso passando um filtro, é apenas uma questão de adicionar códigos ANSI apropriados antes e depois de cada linha:
Não consegui encontrar uma ferramenta que realmente faça isso depois de alguns minutos pesquisando, o que é um pouco estranho, considerando como seria fácil escrever uma.
Aqui está uma ideia usando o C:
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
/* std=gnu99 required */
// ANSI reset sequence
#define RESET "3[0m\n"
// length of RESET
#define RLEN 5
// size for read buffer
#define BUFSZ 16384
// max length of start sequence
#define START_MAX 12
void usage (const char *name) {
printf("Usage: %s [-1 N -2 N -b -e | -h]\n", name);
puts("-1 is the foreground color, -2 is the background.\n"
"'N' is one of the numbers below, corresponding to a color\n"
"(if your terminal is not using the standard palette, these may be different):\n"
"\t0 black\n"
"\t1 red\n"
"\t2 green\n"
"\t3 yellow\n"
"\t4 blue\n"
"\t5 magenta\n"
"\t6 cyan\n"
"\t7 white\n"
"-b sets the foreground to be brighter/bolder.\n"
"-e will print to standard error instead of standard out.\n"
"-h will print this message.\n"
);
exit (1);
}
// adds character in place and increments pointer
void appendChar (char **end, char c) {
*(*end) = c;
(*end)++;
}
int main (int argc, char *const argv[]) {
// no point in no arguments...
if (argc < 2) usage(argv[0]);
// process options
const char options[]="1:2:beh";
int opt,
set = 0,
output = STDOUT_FILENO;
char line[BUFSZ] = "3[", // ANSI escape
*p = &line[2];
// loop thru options
while ((opt = getopt(argc, argv, options)) > 0) {
if (p - line > START_MAX) usage(argv[0]);
switch (opt) {
case '?': usage(argv[0]);
case '1': // foreground color
if (
optarg[1] != 'application 2>&1 | utf8-colorize -1 2 &
'
|| optarg[0] < '0'
|| optarg[0] > '7'
) usage(argv[0]);
if (set) appendChar(&p, ';');
appendChar(&p, '3');
appendChar(&p, optarg[0]);
set = 1;
break;
case '2': // background color
if (
optarg[1] != '#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
/* std=gnu99 required */
// ANSI reset sequence
#define RESET "3[0m\n"
// length of RESET
#define RLEN 5
// size for read buffer
#define BUFSZ 16384
// max length of start sequence
#define START_MAX 12
void usage (const char *name) {
printf("Usage: %s [-1 N -2 N -b -e | -h]\n", name);
puts("-1 is the foreground color, -2 is the background.\n"
"'N' is one of the numbers below, corresponding to a color\n"
"(if your terminal is not using the standard palette, these may be different):\n"
"\t0 black\n"
"\t1 red\n"
"\t2 green\n"
"\t3 yellow\n"
"\t4 blue\n"
"\t5 magenta\n"
"\t6 cyan\n"
"\t7 white\n"
"-b sets the foreground to be brighter/bolder.\n"
"-e will print to standard error instead of standard out.\n"
"-h will print this message.\n"
);
exit (1);
}
// adds character in place and increments pointer
void appendChar (char **end, char c) {
*(*end) = c;
(*end)++;
}
int main (int argc, char *const argv[]) {
// no point in no arguments...
if (argc < 2) usage(argv[0]);
// process options
const char options[]="1:2:beh";
int opt,
set = 0,
output = STDOUT_FILENO;
char line[BUFSZ] = "3[", // ANSI escape
*p = &line[2];
// loop thru options
while ((opt = getopt(argc, argv, options)) > 0) {
if (p - line > START_MAX) usage(argv[0]);
switch (opt) {
case '?': usage(argv[0]);
case '1': // foreground color
if (
optarg[1] != 'application 2>&1 | utf8-colorize -1 2 &
'
|| optarg[0] < '0'
|| optarg[0] > '7'
) usage(argv[0]);
if (set) appendChar(&p, ';');
appendChar(&p, '3');
appendChar(&p, optarg[0]);
set = 1;
break;
case '2': // background color
if (
optarg[1] != '%pre%'
|| optarg[0] < '0'
|| optarg[0] > '7'
) usage(argv[0]);
if (set) appendChar(&p, ';');
appendChar(&p, '4');
appendChar(&p, optarg[0]);
set = 1;
break;
case 'b': // set bright/bold
if (set) appendChar(&p, ';');
appendChar(&p, '1');
set = 1;
break;
case 'e': // use stderr
output = STDERR_FILENO;
break;
case 'h': usage(argv[0]);
default: usage(argv[0]);
}
}
// finish 'start' sequence
appendChar(&p, 'm');
// main loop
// set non-block on input descriptor
int flags = fcntl(STDIN_FILENO, F_GETFL, 0);
fcntl(STDIN_FILENO, F_SETFL, flags | O_NONBLOCK);
// len of start sequence
const size_t slen = p - line,
// max length of data to read
rmax = BUFSZ - (slen + RLEN);
// actual amount of data read
ssize_t r;
// index of current position in output line
size_t cur = slen;
// read buffer
char buffer[rmax];
while ((r = read(STDIN_FILENO, buffer, rmax))) {
if (!r) break; // EOF
if (r < 1) {
if (errno == EAGAIN) continue;
break; // done, error
}
// loop thru input chunk byte by byte
// this is all fine for utf-8
for (int i = 0; i < r; i++) {
if (buffer[i] == '\n' || cur == rmax) {
// append reset sequence
for (int j = 0; j < RLEN; j++) line[j+cur] = RESET[j];
// write out start sequence + buffer + reset
write(output, line, cur+RLEN);
cur = slen;
} else line[cur++] = buffer[i];
}
}
// write out any buffered data
if (cur > slen) {
for (int j = 0; j < RLEN; j++) line[j+cur] = RESET[j];
write(output, line, cur+RLEN);
}
// flush
fsync(output);
// the end
return r;
}
'
|| optarg[0] < '0'
|| optarg[0] > '7'
) usage(argv[0]);
if (set) appendChar(&p, ';');
appendChar(&p, '4');
appendChar(&p, optarg[0]);
set = 1;
break;
case 'b': // set bright/bold
if (set) appendChar(&p, ';');
appendChar(&p, '1');
set = 1;
break;
case 'e': // use stderr
output = STDERR_FILENO;
break;
case 'h': usage(argv[0]);
default: usage(argv[0]);
}
}
// finish 'start' sequence
appendChar(&p, 'm');
// main loop
// set non-block on input descriptor
int flags = fcntl(STDIN_FILENO, F_GETFL, 0);
fcntl(STDIN_FILENO, F_SETFL, flags | O_NONBLOCK);
// len of start sequence
const size_t slen = p - line,
// max length of data to read
rmax = BUFSZ - (slen + RLEN);
// actual amount of data read
ssize_t r;
// index of current position in output line
size_t cur = slen;
// read buffer
char buffer[rmax];
while ((r = read(STDIN_FILENO, buffer, rmax))) {
if (!r) break; // EOF
if (r < 1) {
if (errno == EAGAIN) continue;
break; // done, error
}
// loop thru input chunk byte by byte
// this is all fine for utf-8
for (int i = 0; i < r; i++) {
if (buffer[i] == '\n' || cur == rmax) {
// append reset sequence
for (int j = 0; j < RLEN; j++) line[j+cur] = RESET[j];
// write out start sequence + buffer + reset
write(output, line, cur+RLEN);
cur = slen;
} else line[cur++] = buffer[i];
}
}
// write out any buffered data
if (cur > slen) {
for (int j = 0; j < RLEN; j++) line[j+cur] = RESET[j];
write(output, line, cur+RLEN);
}
// flush
fsync(output);
// the end
return r;
}
Acho que é tão eficiente quanto você vai conseguir. O write() precisa fazer uma linha inteira com as seqüências ANSI de uma só vez - testando isso com forquilhas paralelas levadas a intercalar se as sequências ANSI e o conteúdo do buffer fossem feitos separadamente.
Isso precisa ser compilado -std=gnu99 , pois getopt não faz parte do padrão C99, mas faz parte do GNU. Eu testei isso um pouco com garfos paralelos; essa fonte, um makefile e os testes estão em um tarball aqui:
Se o aplicativo que você usa com logs para erro padrão, lembre-se de redirecionar também:
%pre%Os arquivos .sh no diretório de teste contêm alguns exemplos de uso.